RACHEL MARTIN, HOST:

It has been an extraordinary 48 hours in an already extraordinary presidential campaign. Late Friday, a 2005 tape surfaced of Donald Trump, the Republican nominee, talking about women in vulgar and sexually aggressive terms. Republican leaders started breaking away from him in droves, plunging his party into chaos with only 30 days left before the election. And did we mention there's a presidential debate tonight? NPR political correspondent Mara Liasson is on the line now to talk through it all.

Good morning, Mara.

MARA LIASSON, BYLINE: Good morning, Rachel.

MARTIN: Where does the GOP stand on Trump this morning?

LIASSON: Right now, more than two dozen elected Republicans are calling on Trump to step aside, including two Senate candidates from battleground states, Darryl Glenn from Colorado and Joe Heck of Nevada. There are Republicans who are saying they will no longer vote for him, but most Republicans are condemning his remarks without unendorsing Trump. And House Speaker Paul Ryan, who has been twisting himself into knots about Trump for months, said he was sickened by the audiotape, but he has not withdrawn his support. And at a Ryan rally in Wisconsin yesterday where Trump was supposed to attend but didn't come, Ryan got heckled by Trump supporters. And in another sign of how deep the split is inside the GOP, there's a new poll out today by Morning Consult - it's been taken since the audiotape came out. Three-quarters of Republican voters think the party should continue to stand by Trump.

MARTIN: But this is different. Why? I mean, we've heard Donald Trump make incendiary remarks for months. We've heard him disparage women before. How is this different?

LIASSON: That's a really good question. This is different in degree but not in kind. It's cruder and lewder, but there have been so many other offensive, denigrating comments that he's made. This does seem to be a tipping point. It crossed so many lines. He's bragging about sexual assault, about grabbing women's genitals, about how when you're a star, he says, you can do anything with women - talk about a rigged system.

But ironically, this tape, which might be the undoing of Donald Trump, came in a conversation with a relative of Jeb Bush's. You know, Billy Bush, who's the host of "Access Hollywood," who's on that tape with Trump, is a cousin of Jeb Bush's. So you have to wonder - why, during the primaries, the Jeb Bush oppo research people didn't just pick up the phone and called Jeb's cousin?

MARTIN: So if there were conversations happening about how to replace Donald Trump on the ticket - I mean, is that even possible at this point?

LIASSON: It's very hard, almost impossible, according to election lawyers that NPR has talked to. The rules say you can get a candidate off the ballot in cases of death, incapacitation or declination, meaning he would voluntarily step down. And, as you said, Donald Trump has said he has no intention of dropping out. He said, the media and the establishment want him to but he will never abandon his supporters. And don't forget - voting has already begun in more than 10 states.

MARTIN: Yeah. So this story consumed a lot of attention over the past few hours. But there was a revelation on the Clinton side, too, this release of emails by WikiLeaks. What did we learn from that?

LIASSON: We learned - by the way, these are hacked emails of John Podesta, her campaign chairman's email account. This came on the same day that the administration formally accused Russian security agencies of authorizing the hacking of Democratic Party officials in order to affect the U.S. elections and hurt Hillary Clinton. In these alleged excerpts of her private speeches to Wall Street banks, her paid speeches, she talks about how she's for free trade and open borders. She's sympathetic to bankers. And these tapes are - these excerpts are problematic. You can see why she didn't want them released during the primaries when she was battling Bernie Sanders. This really underscores her weaknesses with honesty and trustworthiness. It could hurt her with young people, with Sanders supporters, blue-collar Democrats. And she will certainly be asked about this tonight.

MARTIN: So just briefly, Mara, let's think about tonight - lots of people going to watch because the stakes are really high. What are you going to be looking for?

LIASSON: This is a very tricky format. It's a town hall debate. Ordinary people, in addition to the moderators, will be asking questions. And that makes it harder for the candidates to attack each other when an ordinary voter is asking you to talk about how you will make their lives better. So I'm watching to see how both candidates navigate this format.

MARTIN: NPR national political correspondent Mara Liasson. Thanks so much, Mara.

LIASSON: Thank you.

MARTIN: As we mentioned, the second presidential debate is tonight. Our colleague Michel Martin will walk through the dramatic events of the last 48 hours in the run-up to the debate. That special will air tonight on many NPR stations from 8 to 9 Eastern Time. Transcript provided by NPR, Copyright NPR.

NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.