ARI SHAPIRO, HOST:
About an hour and a half after President Obama met Bernie Sanders at the White House, Obama endorsed Hillary Clinton for president. Today's announcement was ready to go in a pre-produced video.
(SOUNDBITE OF ARCHIVED RECORDING)
BARACK OBAMA: Look; I know how hard this job can be. That's why I know Hillary will be so good at it. In fact, I don't think there's ever been someone so qualified to hold this office. She's got the courage, the compassion and the heart to get the job done. And I say that as somebody who had to debate her more than 20 times.
SHAPIRO: NPR national political correspondent Mara Liasson is back here in the studio once again to talk about this latest sign the general election is on. Hi, Mara.
MARA LIASSON, BYLINE: Hi, Ari.
SHAPIRO: This endorsement was clearly done hand-in-hand with the Clinton campaign. Did the candidate herself say anything about it?
LIASSON: Yes, she did to our own Tamara Keith today in an exclusive interview when she talked about what she wants Obama to do for her in the campaign.
HILLARY CLINTON: I know he is raring to get out there and start campaigning, and I really look forward to campaigning with him.
LIASSON: That is the understatement of the year...
LIASSON: ...Because President Obama is very popular with the part of the Democratic base that Hillary Clinton really needs to win over, and that is young people. Bernie Sanders just clobbered her with young people during the primaries.
Obama is also a popular sitting president whose approval ratings are hovering around 50 percent. And Clinton and Obama are going to start campaigning together very soon. They're going to go to Green Bay, Wis., on Wednesday, the day after the last primary here in the District of Columbia next Tuesday.
As to what role she envisions for Bernie Sanders - maybe a primetime speaking slot at the convention. She wouldn't say. She'd only say, we have a lot to discuss.
SHAPIRO: Bernie Sanders is still running though.
LIASSON: He is still running, and he was at the White House today and on Capitol Hill meeting with Democratic Senate Leader Harry Reid. He's holding a rally tonight in Washington, D.C. And the effort of the White House and the Clinton campaign and other Democratic leaders has been to get Sanders to exit the race without antagonizing his supporters so the party can unite.
Today Sanders didn't say anything about leaving the race. Up until now, he said he wants to stay until the convention. But he was very conciliatory when he emerged from the White House, and he seemed to be going out of his way to communicate to his supporters that he did not feel mistreated.
(SOUNDBITE OF ARCHIVED RECORDING)
BERNIE SANDERS: What they said in the beginning is that they would not put their thumb on the scales. And in fact, they kept their word, and I appreciate that very, very much.
SHAPIRO: It seems that other prominent Democrats have moved on from the primary though. Their eyes are on Donald Trump.
LIASSON: Yes, that's right. Now that Clinton has beaten Sanders by every metric he has laid down for her - pledged delegates, votes cast contests won - now there's going to be a lot of other big, prominent progressive leaders who will join Clinton on the campaign to defeat Donald Trump - first and foremost Elizabeth Warren, who is as much of a hero to the left wing of the party as Sanders is. She is endorsing Hillary Clinton tonight.
Sanders then will have to decide what role he wants to play. He has a big role to play at the convention, designing the platform. He also has to decide if he will become a full partner to Clinton the way she did with President Obama eight years ago.
SHAPIRO: NPR national political correspondent Mara Liasson - thanks, Mara.
LIASSON: Thank you. Transcript provided by NPR, Copyright NPR.