WILLIAM BRANGHAM: Good evening.

I'm William Brangham.

Judy Woodruff is away.

On the "NewsHour" tonight: one million species at risk.

The United Nations lays out how humans are accelerating the potential of extinction for species across the planet.

Then: a dual look at rising tensions.

North Korea launches a test missile, and the U.S. moves an aircraft carrier into the Persian Gulf sooner than expected.

Plus, Amy Walter and Tamara Keith join us to analyze a busy weekend of campaigning by the 2020 presidential hopefuls.

And masterworks by artist Jean-Michel Basquiat now on display in the neighborhood where he got his start, New York's East Village.

MICHAEL HOLMAN, Filmmaker: Unlike a lot of us, who were just here experimenting with art and our, our voice as artists, Jean-Michel Basquiat knew early on, before any of us, that he was going to be famous.

WILLIAM BRANGHAM: All that and more on tonight's "PBS NewsHour."

(BREAK) WILLIAM BRANGHAM: A million plant and animal species are on the edge of extinction.

That's according to a new United Nations report out today on biodiversity.

Scientists attributed the unprecedented threat to the -- quote -- "relentless pursuit of economic growth."

We will have more on the devastating impact human actions are having on nature right after the news summary.

The U.S. has deployed an aircraft carrier to the Middle East amid reports Iran was preparing to possibly attack U.S. troops in the region.

National Security Adviser John Bolton issued a statement Sunday night, saying the U.S. will -- quote -- "send a clear and unmistakable message to the Iranian regime that any attack on United States interests will be met with unrelenting force."

And today, while in Finland, Secretary of State Mike Pompeo said the U.S. has seen enough evidence to cause concern.

MIKE POMPEO, U.S. Secretary of State: We have continued to see activity that leads us to believe that there's escalation that may be taking place.

So we're taking all the appropriate actions both from a security perspective, and well as our ability to make that sure the president has a wide range of options in the event that something should actually take place.

WILLIAM BRANGHAM: We will have more on the U.S. military moves later in the program.

Back in this country, a bipartisan group of more than 370 federal prosecutors have signed a statement saying that President Trump would have been charged with obstruction of justice if he were not president.

Special counsel Robert Mueller declined to charge Mr. Trump with obstruction, but he didn't exonerate him.

Meanwhile, Attorney General William Barr missed today's deadline to hand over Mueller's full, unredacted report on his Russia investigation.

The House Judiciary Committee will vote Wednesday on whether to hold Barr in contempt of Congress.

President Trump's former personal lawyer Michael Cohen reported to federal prison in New York today.

He was sentenced to three years for lying to Congress and for violating campaign finance law by arranging hush money payments for two women who claimed to have had affairs with Mr. Trump.

Cohen took one final swipe at his former boss as he was swarmed by reporters outside his New York City apartment.

MICHAEL COHEN, Former Attorney/Fixer For Donald Trump: I hope that when I rejoin my family and friends, that the country will be in a place without xenophobia, injustice and lies at the helm of our country.

There still remains much to be told, and I look forward to the day that I can share the truth.

WILLIAM BRANGHAM: Cohen cooperated with the Mueller probe and with separate ongoing state investigations into the Trump Organization and into spending on the president's inauguration.

And late today, the Treasury Department denied a request from House Democrats to release President Trump's tax returns.

Treasury Secretary Steven Mnuchin said the request lacked a legitimate legislative purpose.

Investigators in Russia are trying to piece together what caused a plane to crash-land in Moscow yesterday and burst into flames, killing at least 41 people.

Survivors fled for their lives as smoke billowed from the Aeroflot plane.

Investigators recovered the jet's flight recorders, but haven't yet been able to pinpoint the cause of the disaster.

SVETLANA PETRENKO, Russian Investigative Committee (through translator): Investigators are looking at different versions of the incident, that the pilot and other staff were underqualified, that the plane was broken, and bad weather conditions.

WILLIAM BRANGHAM: Russian media reported that the pilot said the plane lost radio communications after it was struck by lightning.

And there was a tense calm in Gaza today, after Hamas announced a cease-fire deal with the Israeli government.

Violence over the weekend killed nearly 30 people.

It was the deadliest fighting since the 2014 war.

Some Palestinians began the Muslim holy month of Ramadan among ruins, as families buried some of the 25 who died.

Most were civilians.

The Israeli government claimed its strikes targeted militants.

Palestinian rockets also killed four Israeli civilians.

Turkey's top election board today voided the victory of an opposition candidate in Istanbul's mayoral election, and ordered a new vote for June 23.

President Recep Tayyip Erdogan's party had challenged the legitimacy of the election after it narrowly lost.

Turkey's main opposition party said today's ruling amounted to -- quote -- "plain dictatorship."

On Wall Street today, concerns over an escalation in the U.S. trade war with China pushed stocks lower, a day after President Trump threatened to impose more tariffs on Chinese goods.

The Dow Jones industrial average lost 66 points to close at 26248.

The Nasdaq fell more than 40 points and the S&P 500 slipped 13.

And a new royal baby has been born.

Meghan, the duchess of Sussex, gave birth to a baby boy early this morning.

Well-wishers gathered outside Windsor Castle, holding signs and balloons, and drinking champagne to celebrate the news.

Prince Harry told reporters they will share the baby's name in the coming days.

PRINCE HARRY, Duke of Sussex: It's been the most amazing experience I can ever have possibly imagined.

How any woman does what they do is beyond comprehension.

But we are both absolutely thrilled and so grateful to all the love and support for everybody out there.

WILLIAM BRANGHAM: Their baby is seventh in line to the British throne, and is Queen Elizabeth's eighth great-grandchild.

Still to come on the "NewsHour": the devastating effects humans may have on up to one million species; a look at the recent military activity involving Iran and North Korea; Amy Walter and Tamara Keith on the race for 2020; and much more.

Mother Nature is under threat from human activity as never before.

More species are now threatened with extinction than at any other point in human history.

That grim assessment comes from a sweeping new report issued by a panel of experts convened by the United Nations.

Among its findings, nearly a quarter of plant and animal species are threatened, many within decades.

That includes more than 40 percent of amphibian species and more than a third of marine mammals.

Much of this is caused by human activity, farming and fishing and mining, as well as the use of fossil fuels that contribute to pollution and climate change.

It's led to forests being cut down, and agricultural land being degraded, making large parts of the world less able to grow food.

The report says that more than a third of fish stocks are being pulled out of the oceans at unsustainable levels.

To better understand what's happening, I spoke earlier today with one of the many authors of the report.

Patricia Balvanera is with the National University of Mexico.

We spoke from Paris, where the report's findings were issued.

And I began by asking what she saw as the most striking part of the report.

PATRICIA BALVANERA, National University of Mexico: And what is really amazing is not only that a thousand -- sorry -- a million species are being threatened, but also that the impacts of these laws really trickle down to so many dimensions and to so many people on Earth.

WILLIAM BRANGHAM: I know you have been studying this for a while, but do the severity of these results surprise you?

PATRICIA BALVANERA: So, the report indicates that one million species are being threatened.

And we are talking about the wide range of species.

We have known for a while that, for instance, large vertebrates like lions and elephants, have been threatened.

We all have heard about the bears.

We recently have information of how insects are declining.

And I remember, when I was a kid, every time we had a trip in the car, the windshield was full of insects.

But this is not true anymore.

Why should I care about not having insects?

Well, a large fraction of our agriculture production depends on these tiny insects that pollinate the flowers and then that produce the fruit.

So, almonds, apples, some important contribution to tomatoes depends on these pollinators.

And we are really not aware of how this is having a huge impact in agriculture productivity, for example.

WILLIAM BRANGHAM: This report points the finger very directly at us, at human activity on the planet.

Can you give us more detail about what it is that we're actually doing that's driving these changes?

PATRICIA BALVANERA: Yes, let me give you an example.

One of the main drivers of change in nature is the change of how we use the land or the sea.

So, for instance, we are transforming 75 percent of the land on Earth for production of food, production of crops, production of cattle mainly.

And this is 75 percent of the land.

So what does it mean?

We can produce more food.

Actually, the value of crops has increased by three times since 1970.

But what -- we have eroded the potential of nature to support this productivity.

And so the land is degraded, biodiversity is degraded, so we will not be able to continue producing food at the same rate, because we have eroded that ability to provide food.

WILLIAM BRANGHAM: We know we can address climate change by moving to renewable types of energy, but with things like farming and fishing and mining, can those things be done in a different way that doesn't threaten so many species?

PATRICIA BALVANERA: There are very different ways to produce food.

So, today, we use the language of mainstreaming biodiversity into agriculture, into fisheries, into forestry, into tourism.

And this means producing food from agricultural fisheries, for example, in a way that we are - - is friendly with biodiversity.

So, for instance, in Mexico, where I come from, there are very diverse crop systems, where you have maize, beans, squash, and up to 10 or 20 species in the same plot.

And so this produces probably a slightly lower yield, but a huge diversity of crop foods and also in a much more secure way.

Even if the climate is drier or colder, there will be many things to eat, even if it's at cost of a slightly lower yield.

WILLIAM BRANGHAM: But those activities are done this way now because the people and the nations who do them think it's in their economic interest to do this, meaning that there's going to be big incentives to maintain business as usual.

PATRICIA BALVANERA: Absolutely.

So what we were able to show in the report is that the global economy has grown four times, trade has grown 10 times, and that consume -- per capita consumption is very unequal.

People in more developed countries consume up to four times more than people in least developed countries.

So there are very strong interests against changing the way we produce, and, very particularly, a large fraction of agriculture production or fisheries or forestry production is in the hands of a few very large corporations.

But it doesn't mean, by being large, they are not interested in making change.

So by talking directly to these very large corporations, it is possible to make some of these changes possible.

WILLIAM BRANGHAM: Sir Robert Watson, who was the chairman of this panel, said: "We are eroding the very foundations of our economies, livelihoods, food security, health and quality of life worldwide."

I don't mean to sound overly dramatic about this, but he is describing this as a threat to our very way of life.

Do you see it the same way?

PATRICIA BALVANERA: Yes.

So the most striking headline is that the life support system provided by nature that is really holding all the needs of humanity and all the organisms living on Earth is deeply threatened.

So this means there's a threat to our everyday lives, to our economies, to our well-being.

WILLIAM BRANGHAM: All right, Patricia Balvanera of the National University of Mexico, thank you very much.

PATRICIA BALVANERA: It was my pleasure.

Thank you so much to all of you.

WILLIAM BRANGHAM: This weekend saw new and somewhat foreboding developments relating to two flash points of American foreign policy, Iran and North Korea.

We will get to North Korea and its missile launch in a moment, but, first, last night, an unusual statement from National Security Adviser John Bolton announced that a carrier strike group was being moved into the Persian Gulf because of unspecified threatening actions by Iran.

Here to unpack all of this is foreign affairs correspondent Nick Schifrin.

Welcome.

So, the U.S. says, we have got this response we have to have against Iran.

What is it exactly are we deploying there?

NICK SCHIFRIN: So you mentioned it, a carrier striker.

This is the USS Abraham Lincoln and about a half-dozen other ships.

And the carrier strike group that sails together really is one of the most visible and potent, frankly, aspects of U.S. military might.

Alongside that is a bomber task force, a collection of B-1 or B-52 bombers.

And what we saw from National Security Adviser John Bolton in that unusual statement last night -- and, by the way, it's unusual not only when it came out, but also the fact that the national security adviser announced military movements like this.

He said this was designed to send a clear and unmistakable message that any attack will be met with -- quote -- "unrelenting force."

So military officials I spoke to today say that the Abraham Lincoln carrier strike group was on the way to the Middle East, but this advanced that by a few weeks, so they will get there earlier.

And the Air Force officials we spoke to today say they're still figuring out exactly which planes will get there when, but this will increase their lethality in the region.

So, bottom line, as one military official put this, this is a significant and important deterrence against Iran.

And as one regional diplomat told me, this is really a new phase in the U.S. campaign against Iran in the region.

WILLIAM BRANGHAM: As you mentioned, John Bolton and Mike Pompeo over the last few days have said, we have got this evidence that Iran is up to something, and that's why we have to act.

What evidence are they citing?

NICK SCHIFRIN: So the U.S. officials I'm speaking to cite a few things generally.

They say that these are threats to U.S. assets in the region, specifically the Persian Gulf, and the U.S. allies, Saudi Arabia, the United Arab Emirates.

And those are two countries that Iran has threatened for working with the United States as part of the U.S.' maximum pressure campaign against Iran.

The Pentagon spokesman Charles Summers came out just a few hours ago and said specifically that there's heightened Iranian readiness to conduct offensive operations against U.S. forces.

So there's also a threat against U.S. forces, according to the Pentagon.

WILLIAM BRANGHAM: Has there been any criticism of this move?

NICK SCHIFRIN: There are a few criticisms.

I spoke with many Iran experts today, and they specifically said they're not sure they can trust John Bolton, the national security adviser, when he said cites this intelligence.

Bolton has been criticized in the past for manipulating intelligence, including by some of his allies.

And also he has consistently talked about regime change in Iran.

And that leads to criticism number two.

Javad Zarif, the Iranian foreign minister, has talked about the U.S. increasing the chances of confrontation.

And some Democratic senators came out today and said, this is a drumbeat to war.

We worry that the administration is repeating what the U.S. did before Iraq in 2003.

The U.S. says, the administration says, people I'm talking to say and Bolton specifically says, we are not looking for war.

The Pentagon said today, we are not looking for war.

But the fact is, the tensions are increasing and the U.S. is increasing its military president in the region.

WILLIAM BRANGHAM: I mean, we know that, from day one of the Trump administration, they have been, as you say, exerting a maximum force campaign against Iran.

Given that, where does this recent move fit into that context?

NICK SCHIFRIN: So, this -- it will be one year almost exactly, on Wednesday, that the U.S. pulled out of the Iran deal.

In the last month, the U.S. has labeled Iran's Revolutionary Guard Corps, the IRGC, a terrorist organization, and it has sanctioned every country in the world that will continue to import Iranian oil.

The U.S. says that this maximum pressure is to try to get Iran to the table again, and/or to really significantly weaken the government and the economy.

So far, Iran has not responded to any of these in any kind of dramatic way.

And it is still abiding by the restrictions imposed on it by the nuclear deal.

But what U.S. officials are worried about right now is that Iran may decide to take a dramatic step or even perhaps a violent response in the region.

And U.S. and European officials are talking about fearing that Iran will restart one of its enrichment programs, possibly.

And so this is a tense moment.

And, frankly, William, it's going to get even tenser.

U.S. officials tell me they will in impose more sanctions on Iran on Wednesday.

Iran is promising to unveil some kind of response or some kind of new announcement on Wednesday for the Iran nuclear deal anniversary.

And so, really, we are in a cycle of confrontation right now.

WILLIAM BRANGHAM: OK, let's shift gears a little bit.

North Korea late Friday night, we saw them launch a missile, this coming in the context, of course, of these repeated Trump-Kim summits where we're trying to denuclearize that country.

How significant is that launch from Friday?

NICK SCHIFRIN: So U.S. officials tell me this is not a new missile.

And you heard from the president this weekend over Twitter and his senior aides all weekend saying that, look, this is not a big deal.

They downplayed it.

And they downplayed it because they said it's not an ICBM, not an intercontinental ballistic missile.

Therefore, it couldn't threaten the United States.

And, therefore, it also wasn't a break of Kim Jong-un's promise not to test an ICBM.

But -- there's a lot of buts.

This is the first launch in more than 500 days.

So it's significant, just in and of itself.

Even if this missile can't threaten the U.S., it can threaten U.S. allies, like Japan and South Korea.

And it is a violation, by the way, of U.N. Security Council resolutions.

And it may not break Kim Jong-un's promise not to test ICBMs.

But it does break his promise not to increase tensions with South Korea.

And that is a promise that he has made.

WILLIAM BRANGHAM: So what message is North Korea trying to send with this launch?

NICK SCHIFRIN: There's an internal message to its own people and also to officials who might be skeptical of diplomacy with the United States that: We can still be tough.

And there's an external message.

One is expressing frustration and also sending a warning.

The North Koreans have been upset by U.S.-South Korean exercises, including using surface-to-air defense platform called THAAD that was recently done.

And they're also upset there's been no diplomatic progress.

The president walked away from the table basically in Hanoi, saying that the deal that North Korea was offering was not good enough.

And North Korean experts we spoke today say - - told us, the message is that North Korea wants some diplomatic movement.

North Korea still has a robust weapons program.

It's trying to remind the U.S. of that and a reminder of the U.S. that the North Koreans still have military options moving forward.

WILLIAM BRANGHAM: Nick Schifrin, thanks for bringing us up to speed.

NICK SCHIFRIN: Thank you.

WILLIAM BRANGHAM: Stay with us.

Coming up on the "NewsHour": an uptick in xenophobia in South Africa as election day approaches; speaking with philanthropist Melinda Gates about her new book, "The Moment of Lift"; plus, the work of artist Jean-Michel Basquiat now on display in New York's East Village.

As the list of Democrats running for president now tops more than 20, candidates again hit early primary states this weekend.

Lisa Desjardins will get the take from our Politics Monday duo in a moment.

But, first, Yamiche Alcindor brings up to speed on the latest from the trail.

AUDIENCE: We want Joe!

We want Joe!

YAMICHE ALCINDOR: In South Carolina, chants of "We want Joe."

This weekend, former Vice President Joe Biden made his first campaign stop in the state.

In Columbia, he set out to directly appeal to black voters.

He denounced the -- quote -- "legacy of systemic racism" and referenced his former boss, President Barack Obama.

JOSEPH BIDEN (D), Presidential Candidate: As Barack says, when two equally qualified people, one Jamal and one John, they both apply for a job, and John gets the job.

That's the reality in America.

YAMICHE ALCINDOR: In the early voting state of South Carolina, unlike Iowa and New Hampshire, the majority of Democratic primary voters are black.

South bend, Indiana, Mayor Pete Buttigieg also rallied in South Carolina over the weekend.

Sunday at a high school, he spoke to a crowd in North Charleston.

He later acknowledged that he needs better outreach to black voters.

The mayor has made faith a cornerstone of his campaign.

Earlier on Sunday in Georgia, he attended former President Jimmy Carter's Sunday school.

In Iowa, Vermont Senator Bernie Sanders crisscrossed the state in a series of rallies.

He pushed back on Vice President Biden once saying Biden has the most progressive record in the race.

In an interview with ABC's "This Week," Sanders didn't hold back.

SEN. BERNIE SANDERS (I-VT), Presidential Candidate: Joe voted for the war in Iraq.

I led the effort against it.

Joe voted for NAFTA and permanent normal trade relations, trade agreements with China.

I led the effort against that.

If you look at Joe's record, and you look at my record, I don't think there's much question about who's more progressive.

YAMICHE ALCINDOR: A host of other candidates also campaigned in Iowa this weekend, including Massachusetts Senator Elizabeth Warren, Minnesota Senator Amy Klobuchar and former Representative Beto O'Rourke of Texas.

Meanwhile, at an NAACP event in Detroit, Kamala Harris went after President Trump's rhetoric.

SEN. KAMALA HARRIS (D-CA), Presidential Candidate: Let's speak truth here and today.

This president isn't trying to make America great.

He's trying to make America hate.

YAMICHE ALCINDOR: Today, New Jersey Senator Cory Booker released a sweeping gun control agenda, with more than two dozen policy proposals.

One would require all gun owners to be licensed by the federal government.

In a statement, Booker said -- quote -- "I am sick and tired of hearing thoughts and prayers for the communities that have been shattered by gun violence.

It is time for bold action."

With more than 20 candidates vying for 20 spots in the first Democratic debates in June, presidential hopefuls are trying to break through to voters.

For the "PBS NewsHour," I'm Yamiche Alcindor.

LISA DESJARDINS: That is a lot to take in.

Thank goodness it is time for Politics Monday to help.

I'm joined by Amy Walter of The Cook Political Report and host of "Politics With Amy Walter" on WNYC Radio.

And Tamara Keith of NPR, she co-hosts the "NPR Politics" podcast.

Thank you both.

Let's just jump right into this.

Amy, I think Democrats have now gotten past large field, I don't know, epic, biblical.

AMY WALTER, The Cook Political Report: We're - - yes.

Yes.

Mammoth.

LISA DESJARDINS: Why is this field not just large, but extra large?

AMY WALTER: There are a whole lot of reasons.

We could spend the next hour talking about why the field is as big as it is.

The most obvious is, look how successful Bernie Sanders and Donald Trump were in 2016, two candidates that nobody gave any shot of getting where -- how far they got in the process.

So there's certainly a sense of, well, if they could do it, I could do it.

But I think there's also a sense among a lot of Democrats that beating Donald Trump is so important, it's beyond just putting a Democrat in the White House, that they see Donald Trump as essentially an existential threat to the country, and that they want to be the one that can make sure that the right candidate is there to beat him.

So finding that perfect candidate to beat Donald Trump is more important now than ever.

And, finally, I think the party, which used to play a really big role in helping to narrow the field and thin the field, well, it doesn't have much power anymore, especially now that people can raise a whole bunch of money with these things, right, these smartphones.

And they can bypass the traditional money gatekeepers.

It can keep people in the race a lot longer.

TAMARA KEITH, National Public Radio: Yes, one thing I would just add is that, in 2016, Jeb Bush on the Republican side came out, and he wanted to have this sort of shock and awe.

He was going to have all this money and scare away the rest of the field.

And he didn't .

There was a historically large field running in 2016 on the Republican side.

Well, part of what this 22-, 21-, 24-person field on the Democratic side tells me is that there's no single candidate that is scaring everyone else out of the field.

Everyone thinks that they have a chance.

And no one -- this really says that no one was afraid that Joe Biden was going to run for president and didn't run because of it.

In fact, a huge number of people are running for president.

And they believe that they have a shot.

AMY WALTER: Yes.

LISA DESJARDINS: It's interesting, Tam.

As we heard in Yamiche's report, there's a lot of attention on South Carolina.

You said no single candidate is scaring the field.

I wonder if no single state is owning the field.

Why is South Carolina and why are African-American voters in particular getting so much love?

TAMARA KEITH: Well, they are important in the primary, certainly.

African-American voters are very well represented among Democrats in important states like South Carolina, which is an early state, Latino voters in Nevada, another early state.

Then you get to California, which is this big, diverse state.

And then also what Hillary Clinton found when she was running in 2016 is that she was able to win in all of the Southern states with large African-American populations on the Democratic side.

And so a lot of candidates are looking and saying, OK, maybe Iowa and New Hampshire are not my state, but if I can just make it past Iowa, New Hampshire, there are other states where maybe they will have more appeal or they will be able to be better represented.

And also those very same voters are also a critical part of the Democratic electorate in the general election.

AMY WALTER: Yes.

And, remember, South Carolina is important.

It comes on a Saturday.

Three days later is Super Tuesday.

So beyond just being the place where you have for the first time a majority of voters that are African-American, it is momentum to take you into Super Tuesday, which has over 1,690 delegates up for grabs on Super Tuesday.

Many of the states on Super Tuesday also have overwhelmingly diverse electorates.

It's California.

It's Texas.

It's Alabama, Arkansas, Georgia, North Carolina.

So, doing really well in South Carolina sets you up really well, because you do.

You sort of have to turn right on a dime to go into a lot of big states, where you're not going to have a whole lot of time to introduce yourself.

LISA DESJARDINS: And I have got a soft spot for the politics of South Carolina.

They are never boring.

AMY WALTER: Yes.

Yes.

And food.

LISA DESJARDINS: And food.

That's right.

Now, Amy, I want to ask you.

Earlier in the show, Nick Schifrin reported on two big flash points in the world, just two of the several flash points, in this case, North Korea and Iran.

But we don't see voters responding to foreign policy in polls.

Why is that not really an issue in this campaign?

And what are issues for voters right now?

AMY WALTER: So I think, back in 2008, foreign policy was a big issue, because the Iraq War was so unpopular, and there was a clear dividing line between Barack Obama and Hillary Clinton on who supported the war.

And so that made that a big issue.

Now, we don't have that same issue dominating the issue set for voters, Democrat or Republican.

Instead, what we're finding is, what Democrats are really, really concerned about -- there's a poll that just came out today, NBC/Wall Street Journal -- overwhelming top issue for Democrats, health care.

Overwhelming top issue for Republicans, immigration, not surprising.

Those are the things that are taking up most of the oxygen.

When we look more broadly, it's health care and jobs and the economy that are the top two issues.

LISA DESJARDINS: Tam, what do you see?

TAMARA KEITH: Yes, and this is just something that people, regular people in America that these candidates are coming into contact with on a regular basis, they just aren't asking about foreign policy.

And not to go back to 2016 again and again, but I was following Hillary Clinton's campaign.

She is a former secretary of state.

She could talk about foreign policy until she is blue, and she'd still have more to say.

And yet she didn't talk about it very often on the trail, and she was almost never asked about it in her town halls.

LISA DESJARDINS: Quickly, as we wrap up, I'm interested.

Looking back at this huge field, it feels like there's so many right now.

How many of these folks are actually going to make it to 2020, do you think?

(LAUGHTER) AMY WALTER: Well, I looked back in 2016.

Again, as Tam said, there was a really big field, 16 candidates.

Five of them dropped out before 2016, so throughout the 2015 year.

These debates are going to be very important, who gets on the stage, how well they do.

At some point, you need money and you need attention.

And even if you have the greatest of intentions, you can't stay in if you don't have those two things.

LISA DESJARDINS: Debates start in June.

How big are those going to be, Tam?

TAMARA KEITH: Oh, well, I mean, there will be 20 people over two nights.

That's literally how big they will be.

But I think, for a lot of voters, they -- they aren't getting to see these candidates.

They're seeing little snippets.

And that will be the first big chance for these candidates to introduce themselves beyond sort of viral videos.

AMY WALTER: Yes, and to see them interact with one another.

TAMARA KEITH: Yes.

AMY WALTER: And it'll probably be the first debates where we will get to see a president live-tweet the other party's debates.

(LAUGHTER) AMY WALTER: Wait for it.

LISA DESJARDINS: There's going to be plenty of tweeting all around.

AMY WALTER: Plenty.

TAMARA KEITH: Oh, yes.

LISA DESJARDINS: Thank you.

And from you as well.

Amy Walter of The Cook Political Report, Tamara Keith of NPR, thank you both.

And I want to let our viewers know, join us tomorrow, when Judy Woodruff will sit down with Democratic presidential candidate Bernie Sanders right here in our studio.

You won't want to miss that.

WILLIAM BRANGHAM: South Africans will vote in their national election on Wednesday, and there could be a strong challenge to the ruling African National Congress.

As special correspondent Fred de Sam Lazaro reports, a new wave of xenophobic attacks has put the issue of immigration front and center.

FRED DE SAM LAZARO: At this campaign rally for the Economic Freedom Party, once the youth wing of the ruling African National Congress, the frustration was evident.

MAN: We are tried of joblessness and poverty in our country.

FRED DE SAM LAZARO: Unemployment in South Africa hovers at 27 percent.

And youth unemployment is nearly double that.

It's felt most acutely in the townships, impoverished settlements built under apartheid to segregate the black, Indian and mixed or colored communities from the minority white population.

Preggie Chetty sells used clothes on the side of the road.

He lost his factory job years ago, now barely ekes out a living, and he blames in part immigrants.

PREGGIE CHETTY, Former Factory Worker: You get a lot of foreigners into the country here.

And they're being paid with a less salary.

And our local guys, they can't get jobs.

FRED DE SAM LAZARO: That sentiment has provoked spasms of xenophobic violence in recent years.

Convenience stores have often been an all-too-convenient target.

These stores are largely owned by immigrants today, as are the wholesalers that supply them.

Ali Osman, who heads a trade association of Somali businesses, says he is grateful to be in South Africa.

ALI OSMAN, Somalia Community Board of South Africa: We came with nothing.

We have been given the opportunity to conduct businesses, freely move around the country, settle wherever we need to settle.

So that is the good part of it.

FRED DE SAM LAZARO: The bad part, he says, is the violence targeting immigrants, who make up about 3 percent of the country's 57 million people.

Over the past decade, hundreds of immigrants have been injured and dozens killed.

Johannesburg's Mayor Herman Mashaba says the problem is economic, not xenophobic.

HERMAN MASHABA, Mayor of Johannesburg: When these foreign nationals come into South Africa, unfortunately, because of the economic situation, where do they go?

They go into poor communities.

And those poor communities, unfortunately, they feel that these people are taking their jobs, or whatever.

FRED DE SAM LAZARO: But many blame Mashaba himself for inciting violence.

The mayor, once an ANC supporter, is now part of the opposition Democratic Alliance.

He's blamed many of the city's problems on an uncontrolled numbers of undocumented foreigners.

This Twitter post was in response to a citizen complaint about poor trash service.

VUSUMUZI SIBANDA, African Diaspora Forum: So, basically, in his tweet, he implied that the dirt is not picked because there are too many migrants.

Now... FRED DE SAM LAZARO: He's blaming the lack of garbage pickup on too many migrants?

VUSUMUZI SIBANDA: Exactly, yes.

You know, government officials, instead of taking accountability for their failures, they then blame the migrants for the social ills like crime and lack of housing.

FRED DE SAM LAZARO: Vusumuzi Sibanda is an immigrant from neighboring Zimbabwe, where a collapsing economy and political turmoil have driven many to flee.

VUSUMUZI SIBANDA: Good morning.

AUDIENCE: Good morning.

FRED DE SAM LAZARO: Sibanda is suing to get children among these migrants, most of them undocumented, into public schools.

It's their right, he insists, and also it is in the host country's interest.

VUSUMUZI SIBANDA: We're actually creating a situation where these children are either going to become, what, criminals, social misfits because they have no education.

What will they do without an education?

FRED DE SAM LAZARO: Why do they come?

LOREN B. LANDAU, University of the Witwatersrand: The migrants come to South Africa for the same reasons that anyone moves, but there are clearly a significant number of people here who are looking for safety.

FRED DE SAM LAZARO: Professor Loren Landau says they are fleeing conflict in Somalia, Congo and elsewhere, but others, including many from South Asia, come to start businesses or ply their skills in the continent's largest economy.

LOREN B. LANDAU: Electricians, builders, others.

But we also see a lot of teachers, doctors, medical professionals who are coming in.

FRED DE SAM LAZARO: Zimbabwe's disintegration dashed any career hopes of people like Fortunate Ndlovu, who once dreamed of becoming a lawyer.

Today, she shares an immaculate one-room shack with her husband, Mandla Sibanda, and their young son.

Together, they support at least five family members back in Zimbabwe.

How has it been in South Africa so far?

FORTUNATE NDLOVU, Zimbabwean Migrant: It's OK because, if you go around, you can get some piece works.

FRED DE SAM LAZARO: Some piece work?

FORTUNATE NDLOVU: Yes.

FRED DE SAM LAZARO: Ndlovu gets occasional work as a house cleaner.

Her husband works in a local restaurant.

FORTUNATE NDLOVU: We just take anything that comes, because half-bread is better than nothing at all.

FRED DE SAM LAZARO: Half-a-bread is better than nothing?

FORTUNATE NDLOVU: Yes.

We are here to work, only to work, not to go and break the law.

FRED DE SAM LAZARO: She says immigrants have been unfairly characterized as lawbreakers.

Mayor Mashaba, for one, has railed against what he calls rampant criminal activity in the city's immigrant population.

But he insists he's not anti-immigrant.

HERMAN MASHABA: This country, the city of Johannesburg, it was built on the back of migrants.

But they must come here legally.

And when they're here, they must respect our laws.

This, for me, is not negotiable.

LOREN B. LANDAU: Clearly,there are criminals among the migrant population.

What you see, however, is, he sends the police out to find migrant criminals, and then parades them, as if all of the criminals in towns are migrants.

Migrants are no more prone, and in fact less prone, to criminal activity than South African citizens.

FRED DE SAM LAZARO: But the arguments around immigration, echoing those heard in the U.S., are likely to get only louder as Election Day nears.

For the "PBS NewsHour," I'm Fred de Sam Lazaro near Johannesburg, South Africa.

WILLIAM BRANGHAM: Fred's reporting is a partnership with the Under-Told Stories Project at the University of St. Thomas in Minnesota.

The Bill and Melinda Gates Foundation is he largest philanthropic foundation in the world.

It has an endowment of $50 billion.

Its reach has been global, focusing on issues like malaria, reproductive health, family planning and education.

Melinda Gates plays a huge role in shaping the organization's focus.

Judy Woodruff spoke with her recently about her new book, which looks at what she's learned in that job and her own personal story.

It's our latest installment of the "NewsHour" Bookshelf.

JUDY WOODRUFF: Melinda Gates, welcome.

The book is "The Moment of Lift: How Empowering Women Changes the World."

Thank you for joining us.

MELINDA GATES, Author, "The Moment of Lift: How Empowering Women Changes the World": Thanks for having me, Judy.

JUDY WOODRUFF: So, this is your first book.

And you weave in your own story with your experiences with women, mostly very, very poor women you have met around the developing world.

What did you want to accomplish with this?

MELINDA GATES: Well, I have been meeting men and women around the world now for 20 years in the foundation's work, and so many women have shared the stories of their lives with me.

And they have really called me to action.

And by sharing their story and a bit about my personal journey, I hope to call other people to action for empowering women around the world.

JUDY WOODRUFF: You plunged, in the early 1980s, into a very male career, dominated career, in computer science and then through the Gates Foundation, after you had children.

And you write about how it took you a while to find your voice as a woman, to advocate for women.

MELINDA GATES: Yes.

JUDY WOODRUFF: Why was that?

Why did it take as long as it did, do you think?

MELINDA GATES: Yes, I think because there's so many things society tells us as women that what we should do, or we should say, or ways we should be.

And I was so lucky to grow up with two parents who said to both the two daughters in the family, one of which was me, and the two sons, you can be anything you want to be.

We could see, as a middle-class family, it was going to be hard to send us a college, but we could.

And I think having a dad who believed in girls in the sciences really helped me see that I could be anything I wanted to be.

And so, even when I would come up against these barriers in society that women face, I knew that my job was to try and break through those.

And in the foundation's work, I didn't originally start with women's issues, because I thought those were the soft issues.

And I was completely wrong.

If we lift up women, they lift up everybody else.

But our systems don't always reach women.

And there are lots of barriers that hold women down.

JUDY WOODRUFF: And that took a while to understand?

MELINDA GATES: It took a while to understand and to learn.

And, partly, I was hearing it for women all over the world, when I'd be out in the developing world talking to women, many different countries in Africa.

But I would come back and look at the data.

And I always thought data was objective.

But data is actually sexist.

We don't actually collect a lot of data about women around the world.

So we don't actually know that much about their lives.

They would often say to me, what about -- what about in this little tiny health clinic where I get vaccines for my kids?

Why can't I get birth control anymore?

Why could I get a contraceptive before, and now I can't?

And they started to tell me that this was a life-and-death emergency for their family.

And the data actually was very thin about what was going on.

But it turned out what the women were telling me was true.

This was a life-and-death emergency in the developing world, and is -- 200 million women want contraceptives, and we don't supply them, as a world, yet.

JUDY WOODRUFF: And speaking of contraceptives and birth control, you are open in the book about your differences with the Catholic Church on these issues, abortion as well.

MELINDA GATES: Mm-hmm.

JUDY WOODRUFF: You even take on the church when it comes to leadership roles for women as priests.

Do you see any movement in the Catholic Church on these issues?

MELINDA GATES: What I know is that when women have access to contraceptives, they time and space the births of their children.

And we know, from the longest piece of longitudinal research in global health, that those families are healthier, the moms, the babies, the families are better educated, the kids are, and the families are wealthier.

And my faith says to me that we believe in loving my neighbor.

And so I have stood up and said what I believe, even with the Catholic Church.

The Catholic Church, because of HIV/AIDS, has allowed condoms to be distributed in the developing world.

But I have met so many women who have told me: I can't negotiate a condom in the context of my relationship with my husband, because I'm either suggesting he's been unfaithful and has AIDS or I have been unfaithful.

And so women have to have the types of tools we have here in the United States, or the primary tool they want in Africa, which has been in the past delivered and still is in some places, is a shot, which is covert from their husbands.

JUDY WOODRUFF: Has that debate shaken your faith, your personal faith?

MELINDA GATES: I have had to wrestle with my faith, and -- before I came out publicly in favor of contraceptives.

But when I realized that it's because of political pressure in our own country and religious belief that we're letting women die in childbirth, we're letting babies die because a woman has them too soon and too often, my faith tells me that I love these people.

And I know I have gotten some beautiful things from the Catholic Church, my roots in social justice.

But this is a piece I disagree with the church on.

JUDY WOODRUFF: You don't name President Trump in the book.

You speak about our president, our current administration.

As you know, this administration is pushing very hard against abortion rights, to limit abortion, make it as restrictive as possible.

The question is, why not go farther and call it what it is?

Why not name the Trump administration?

MELINDA GATES: Well, I have said that I disagree vehemently with the values being put forward by this administration.

So I'm not sure what -- how much stronger I could be.

I'm not running for public office.

But I disagree.

And I disagree in public, and I disagree in private.

And our foundation has worked incredibly well with the Bush administration, the Obama administration, Congress in this administration.

I don't name this administration in my book because I want it to be a timeless book.

I don't name President Bush or former President Obama either.

So what I look for are the places where I can move issues forward.

And I work with people who are like-minded.

Luckily, Congress has held up the foreign aid budget because they know it creates a peaceful and prosperous world and societies all over the world.

JUDY WOODRUFF: One other thing I want to ask you about that you write about is your own effort inside your own marriage to find your own voice, to gain self-confidence.

And you talk about how you wrestle with whether to even share this publicly.

MELINDA GATES: What is true is that Bill and I always believed in equality.

We wanted equality.

And what I write about in the book is, I didn't even realize that when I came into marriage, we came into marriage, we both came from our own biases of the past a little bit about how our households operated as kids.

And so I surprised Bill when I -- we got pregnant with our first child, Jen.

I surprised him and said, I'm going to leave Microsoft.

I said, I'm going to leave and raise our kids.

And Bill was actually the one who said to me, after Jen was six months old, "What else are you going to do?"

Because he knew I had that part of my brain that I also love to work.

But, yes, those conversations aren't always easy.

But we -- I bring them up because we need to have those in our home to make sure that we have equality and to look at what assumptions have we made, and do we need to shift those, as we have kids or things change or we get older or our careers change?

And what I want women to know is, you can have full equality, and you should, in your home, in your workplace and in your community.

And when you do that, it changes the world.

Equality makes a huge difference.

JUDY WOODRUFF: Melinda Gates.

The book is "The Moment of Lift."

Thank you very much.

MELINDA GATES: Thanks, Judy.

WILLIAM BRANGHAM: Finally tonight: More than 30 years after his death, Jean-Michel Basquiat remains one of America's most influential contemporary artists.

He carved a unique style that challenged our views of race, poverty and politics in the U.S. Jeffrey Brown explores a new exhibition showing some of Basquiat's most important work.

It's part of our ongoing arts and culture series, Canvas.

JEFFREY BROWN: New York City's East Village, in the 1970s and '80s, it was known for drugs, crime, homelessness and a vibrant experimental music and art scene.

The heartbeat of it all, Tompkins Square Park.

MICHAEL HOLMAN, Filmmaker: It was like a real central coming together place.

You know, it was a bit of nature in the middle of this teeming city, a place where you could crash if you had nowhere to sleep.

JEFFREY BROWN: Michael Holman is a New York-based artist, writer, filmmaker and musician, and part of a unique generation of artists who called the East Village home, including Kenny Scharf, Keith Haring, and, perhaps most famous of all, Jean-Michel Basquiat.

MICHAEL HOLMAN: Jean-Michel Basquiat was -- I would call him a realized being.

JEFFREY BROWN: It was at a party in 1979 that Holman first met Basquiat, whose graffiti tag SAMO was already well-known on the streets of New York.

Did you feel even then a kind of ambition to grow beyond that?

MICHAEL HOLMAN: Oh, absolutely.

JEFFREY BROWN: Yes.

MICHAEL HOLMAN: Absolutely.

Unlike a lot of us, who were just here experimenting with art and our voice as artists, Basquiat knew early on, early on before any of us, that he was going to be famous.

JEFFREY BROWN: And famous, he became.

Since his death in 1988 at age 27 from a heroin overdose, Basquiat's reputation and the demand for his work have skyrocketed.

His now iconic lines, figures, and handwritten texts are regularly displayed in the world's most renowned museums and galleries.

Two years ago, his untitled 1982 painting of a skull fetched more than $110 million at auction, the most ever for any American artist.

That work and many others were part of a new exhibition that began in Paris, curated by Dieter Buchhart.

DIETER BUCHHART, Curator: His energy is amazing.

His line is inimitable.

His combination with words, collage and assemblage, nobody else did.

It's all under his own aesthetic.

But the way he combined knowledge is so contemporary.

JEFFREY BROWN: Now, the exhibition has come home, in a sense, to Basquiat's old stomping grounds in the East Village of New York in a brand-new private museum owned by the Brant Foundation.

It's housed in a former electrical substation.

Tickets here are free.

The first batch of 50,000 was gone before the exhibition opened.

The works themselves come from museums around the world and private collections, including that of the foundation's founder, Peter Brant, CEO of one of the largest newsprint manufacturers in North America.

He's been buying Basquiat's work since the 1980s.

What did you see in the art at that time?

PETER BRANT, The Brant Foundation: I mean, I thought he was, you know, a great colorist.

I love the way he used the language in his work.

And he'd been billed as a graffiti artist, but I -- if you look at his work, it goes far beyond painting on subway cars.

JEFFREY BROWN: Born in Brooklyn in 1960, Basquiat was the son of a Haitian father and Puerto Rican mother.

He left home as a teenager and began selling hand-painted postcards and T-shirts.

In 1979, he and Holman helped form the rock band Gray, as Basquiat entered a prolific period of creating his own art.

Years later, Holman would help capture those times as a screenwriter for the feature film "Basquiat," directed by another well-known contemporary artist, Julian Julian Schnabel.

Some called Basquiat's paintings primitive, raw, even childlike.

But he was unfazed.

MICHAEL HOLMAN: He also recognized that combining that child's hand and that child's innocence with some of the highly charged issues of race and economic disparity and the particular politics of America, if he would combine those things in a special way, which he did, that he would touch on that third rail.

JEFFREY BROWN: The Brant exhibition reflects those issues, in paintings like The Irony of a Negro Policeman and Per Capita, but there are also lighter pieces, like those of famous boxers he admired.

Just as Basquiat's prices have gone up, so have rents in the East Village.

It and this city have changed dramatically since his time.

Further evidence, The Brant Foundation Museum itself.

He had an aesthetic of the streets.

Is there not a disconnect with seeing him in a -- sold for $110 million, owned by people of wealth, and, you know, in a private museum?

PETER BRANT: I don't see any disconnect, other than it's an example of the American dream.

He's not an artist that's just appreciated by the people that live in this neighborhood.

We're just giving the people in this neighborhood an opportunity to see the work of somebody that came out of this neighborhood.

JEFFREY BROWN: Today, Basquiat continues to be a hero for many-including young people like these who stopped to hear our conversation.

MICHAEL HOLMAN: Being friends with him, hanging out with him was like going to Basquiat university, where you gleaned the power of combining disparate ideas that shouldn't work together, but that do.

JEFFREY BROWN: Jean-Michel Basquiat, the inaugural exhibition at the Brant Foundation, runs through May 15.

For the "PBS NewsHour," I'm Jeffrey Brown in New York.

WILLIAM BRANGHAM: Another exhibition showcasing Basquiat's work is set to open at the Solomon R. Guggenheim Museum in New York next month.

And that's the "NewsHour" for tonight.

A reminder: Tune in tomorrow for Judy's interview with Democratic presidential candidate Senator Bernie Sanders.

I'm William Brangham.

Join us online and again here tomorrow evening.

For all of us at the "PBS NewsHour," thank you, and good night.

END