MARY LOUISE KELLY, HOST:
Now to the 2020 presidential campaign, where the Democratic Party is also trying to assert more unity. It has asked candidates to sign a pledge saying they will run as Democrats and, if elected, serve as Democrats.
So what is this all about? NPR lead political editor Domenico Montanaro is here. And, Domenico, what is up with this? If you're running for the Democratic Party nomination, this is an issue why?
DOMENICO MONTANARO, BYLINE: Well, I mean, there are more than a dozen people running for the Democratic nomination, but it's really about one person. This is about Bernie Sanders. You know, he's a Vermont independent as a senator. He caucuses with the Democrats, but he's not a registered Democrat.
The party briefed the campaigns last week, handed out what they called affirmation forms. They had to be back within a week. Sanders returned and signed his yesterday, pledging that he will run and serve as a Democrat if he wins. And here's what he said Monday on The Breakfast Club, the popular New York morning radio show.
(SOUNDBITE OF RADIO SHOW, "THE BREAKFAST CLUB")
BERNIE SANDERS: The most important thing that has got to happen is that this dangerous president is defeated. I'm going to do everything I can to defeat him. I look forward to winning the Democratic nomination. And if I don't, I will support anybody else who's out there to defeat him. But this guy cannot win another term.
KELLY: OK, so Bernie Sanders looking forward to winning the Democratic nomination, sounding like a Democrat. But, of course, things - not so simple.
MONTANARO: Right. I mean, the day before that, Sanders turned in his affirmation that - Sanders had turned in that affirmation form. He filed to run for re-election for the Senate in 2024 in Vermont as an independent.
Now, it's not unusual for a candidate to file for re-election shortly after Election Day with the Federal Election Commission. They waited a bit so that - they wanted to begin raising money. But the timing here optically - even those close to Sanders admit that it doesn't look great.
And the party, frankly, is asking Sanders to change his - is not asking Sanders to change his party registration in the Senate. And they say that this pledge is for the Democratic presidential nomination. But there are some Democrats who don't like Sanders' sort of ambiguous status.
KELLY: Just briefly, safe to say this is unusual to have a candidate running for Senate as an independent and for president as a Democrat at the same time.
MONTANARO: Yeah. I mean, I can't think of one who's done that in recent memory.
KELLY: And I guess that the challenge here for Democrats is they want to make sure that if Sanders doesn't eventually win the nomination that all of his supporters would go to whoever does, right? I mean, this was an issue in 2016 when he lost the nomination to Hillary Clinton.
MONTANARO: Right. That's the whole big-picture piece of this. And some would like him to go further. In fact, here was Gregory Meeks on CNN. He's a New York congressman and a Hillary Clinton supporter in 2016.
(SOUNDBITE OF TV SHOW, "CNN NEWSROOM")
GREGORY MEEKS: Run as a Democrat. We've asked him on a continuous basis, if, in fact, you want to be the Democratic nominee, you should be a Democrat. If you're not a Democrat, you should not run. You should run as an independent.
MONTANARO: I mean, of course, an independent bid is really difficult. Sanders has made it clear that he doesn't want to have to run as a Democrat that - I mean as an independent for the nomination because it's easier. And he has influenced the party on so many things. And him signing this pledge is really a big step.
And Sanders bristles at this idea that he may have been a cause of Hillary Clinton losing in 2016. He wants all of his supporters to get behind the whoever the nominee is. But he points out that Hillary Clinton's supporters in 2008 - many of them voted for John McCain over Barack Obama. Of course, that didn't matter because it wasn't a close election.
KELLY: So much intrigue. NPR's Domenico Montanaro, thank you.
MONTANARO: You're so welcome.
(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.