from the tisch wnet stolios at licenter in new york, hari sreenivasan. >> sreenivasan: good evening and thanksor joining us. two days after president trump declared a national emergency in order to spend billions of dollars in additiol funding for a wall or barrier along the u.s.-mexico border, he's facing both political and legal challengesta represve adam schiff called the president's declaration "plainly unconstitutional." >> this is the first time a president has tried to declare an emergency when congress explicitly rejected funding for the particular project that the president is advocating. and in saying just the other day that he didn't really need to do this. he just wanted to do it becauseh it would helgs go faster. he's pretty much daring theth court to strik down. it's hard to imagine a poorer case, but i'll say thia, it's going to be a real test for myss.o.p. colleagues in cong and their devotion to the institution. >> sreenivasan: white house senior aiser stephen miller said the president will defend his emergency declaration even if congresvotes to stop him. >> if they pa

from the tisch wnet studios at lincoln center in new york, hari sreenivasan. >> sreenivasan: good evening and thank you for joining us. the governor of virginia, democrat ralph northam, now says he is not one of the people in a racist photo that he apologized for yesterday. at a news conference this afternoon northam said he saw tho in question for the first time yesterday. it is on hisersonal page in s 1984 medical school yearbook showing two men-- one in black face, one in a ku lan robe. >> yesterday i took responsibility for content that appeared on my page of the eastern virginia medical school yearbook that was clearly racist and offensivin he hours since i made my statement, i reflected with mymi and my classmates from the time and affirmed my honclusion that i'm not the person in that. >> sreenivasan: joining us now for more is annie linsky of the washington post. annie, this seems look a little bit of a reversal from what he said yesterday. >> yeah, absolutely. i mean, i think thebig news here is governor northum came out today and said he is notth photographed i very surprising,

i'm hari sreenivasan. thanks for wating. have a good night.tioning sponsored by wnet captioned by media access group at wgbh access.wgbh.org >> pbs newshour weekend is made possible by: bernard and irene schwartz. sue and edgar wachenheim iii. seton melvin. the cheryl and plip milstein family. dr. p. roy vagelos and diana t. vagelos. ithe j.p.b. found rosalind p. walter. g arbara hope zuckerberg. corporate fund provided by mutual designing customized individual and group retirement products. that's why we're you retirement company. additional support has been provided by: and by the corporation for public broadcasting, and by contributions to your pbs station from viewers like you. thank you. m e. pbs. diep tran: i think people aretn aware of vese cuisine, and most people don't want that cuisine to change or don't want to have their understanding of the cuisine to change. because the cuisine is changing all the time. the idea of a, like, this unifying national cuisine, vietnamese cuisine, it doesn't exi. really, it truly doesn't exist. even a

i'm hari sreenivasan. thanks for watching. have a good night. captioning sponsored by wnet captioned by media access groupt bh access.wgbh.org >> pbs newshour weekends made possible by: bernard and irene schwartz.ed sue anr wachenheim iii.in seton me the cheryl and philip milstein family. a . p. roy vagelos and di vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provided by mutual of america-- designing customized indivual and group retirement products. that's why we're your retirementompany. additional support has been provided by: and by the corporation for public broadcaing, and by contributions to your pbs n statom viewers like you. thank you. >> pain. it affects hundreds of millions of us. >> i had terrible tensionfo headachedays on end. >> there are different times in my life where i couldn't walk. >> when you have pain, it's always there. going to be colored bying is pain. >> i've joined forces with therapist d pain management expert lee albert. together, we visit with some people who were

isfrom the wnet studios at lincoln center in new york, hari sreenivasan. >>ni sreenivasan: good e and thank you for joining us. tension continues to rise in ve wnezuela today overther humanitarian aid will be allowed into the country. the national guard tear-gassed ters from both venezuela and colombia who tried to reach bridges between the countries. the clashes happened in the bordering cities of urena incu venezuela and ta in colombia. on the colombian side of the tebridges, opposition prot tried to escort trucks with emergency food and medic aid into venezuela using what leaders call a "humanitarian avalanche." on the venezuelan side of the harder the venezuela national guard injured moretwo dozen people as protestors set fire to buse pbs newshour special correspondent nadja drost is in urena, venezuela. >> i saw one bus being burned and crash into a house, and then the house was set on fire. so i think that for protesters who nted this to be a peaceful event, that thatnc c was lost when some of the actions of the protesters turned violent. however, we

hari sreenivasan reports on what sets the school apart for our education series, "making the grade." >> let's start with glycolysis. >> sreenivasan: on the campus o, xavier univers8-year-old chris webb leads a biology review the night before a major test. >> all you really need to know. >> sreenivasan: webb is helping fellow freshman who, like him, are enrolled in a rigorous pre- medical program. >> i want them to do as best as they can. >> sreenivasan: the scene is familiar one on the campus ofer xaan historically black college the heart of new orleans.>> hat do you think of aerobic respiration? >> sreenivasan: studenz each other on material from tough science classes, the kind of courses that often weed out premedical students. >> i don't want them to do better than me, but when they do, that just makes meze, okay, this competition is really serious. while we're having fun with it, it's alsvery real.an >> sreenivwith a student population of only 3,000, xavien universityes to graduate more african americans who go on to become medical doctors than any other undergraduate institution

from the tisch wnet studios at lincoln center in new york, hari sreenivasan. >> sreenivasan: good evening ajo thank you foing us. as president trump prepares for his second summit with north korea's leader kim jong un in vietnam this week, sec of state mike pompeo said today north korea remains a nuclear threat, contradicting the president's tweet last june th"" there is no longer a nuclear threat from north korea." >> do you think north korea remains a nuclr threat? >> yes. >> but the president said he doesn't-- >> that's not what he said. >> he tweeted, "there's no longer a nuclear threat from north korea." >> right. what he said was that the efforts that had been made in singapore, this commitment that chairman kim made, had substantially taken down the risk to the american people. >> sreenivasan: north korea's state tv released footage today of kim jong un's train departure for vietnam. president trump leaves for thero summit tom he promised a "continuation of the progress made at the firstut summit,"ffered no specifics on north korean denuclearization. vice president mike pence will

opened in london to rave reviews and now it's on broadway where the couple sat down with our hari sreenivasan>> what is this play about? >> it's about three and a half hours long. it's set in northern ireland in 1981. in the middle of the troubles. in the middle of a hunger strike on a farm where the harvest is being brought in. >> there's disappearance at the center of this. and this is based in part on your family history. it seems that families don't really talk about that much. how did this get into the play? >> yeah, they definitely don't. and that was part of how it did come up was because we had been watching a documentary on the disappeared in northern ireland and my uncle's face appeared at the end as they put the faces up of all the people who had been disappeared and my uncle's face came up. i, in that moment, it was only then that the penny really dropped that he was one of them. i'd always known his story but i hadn't really put with two and two together even while watching the documentary. it wasn't until the end i said that's my uncle. it came obviously as a bigger shock to you

from the tisch wnet ncudios at n center in new york, .hari sreenivas >> sreenivasan: good evening and thank you for joining us. what sounded like preising news yeay, that a bipartisan congressional conference committee was clone to agreement order security funding that would avoid another partial government shutdown, today turned into another political standoff. the lead republican negotiator said that one of sticking points in budget talks is now the numberof beds at immigration and customs enforcement detention centers. >> i think the talks are stalled right now. i'm hoping we can get off the dime later today or in the morning because time is ticking away but we've got some problems with the democrats dealing with ice, that is detaining criminalh t come into the u.s. and they want a cap on them. we don't want a cap on that. >> strreenivasan: presidenp slammed democrats for not offering enough border wall funding and wantosg a cap on the detained. democratic sources blamed senate republicans for refusing to compromise on the issue. congress must approve a new spending bill and the pr