JUDY WOODRUFF: Donald Trump continues to drive division in the Republican Party, as new polls have him losing ground in states that will be key to victory.

We look at where the race stands now with Robert Costa. He's the national political reporter with The Washington Post.

Robert Costa, welcome back to the program.

First of all, we know that Reince Priebus, who is the chairman of the Republican Party, made a point of introducing Donald Trump today when he spoke in Erie, Pennsylvania. But at the same time, we have been mentioning the polls are slipping for Mr. Trump. There has been a string of these controversial statements. How worried — or is this party worried?

ROBERT COSTA, The Washington Post: Judy, good to be with you.

The relationship between the party chairman and the GOP standard-bearer remains a pivotal one within the GOP, and my sources tell me that Priebus made a point today to travel from New York to Erie, Pennsylvania, to make sure he showcased his unity with Donald Trump, as some people at the party's upper levels are saying maybe it's time, because of these sliding poll numbers, to distance Republicans, especially in swing states, from Donald Trump.

Priebus said today in Erie that's not true, the party is not moving away from Trump, he's sticking with the nominee.

JUDY WOODRUFF: And so what sort of pressure, Robert, is there on the Republican Party, on the leadership of the party to either work with Donald Trump or to distance themselves from him?

ROBERT COSTA: At the RNC level, they're intertwined, the Trump campaign and RNC, when it comes to fund-raising. So, they have had a close relationship.

The tensions are really more raw when it comes to the congressional ranks. House Republicans have a 59-seat majority. Some members there are privately very edgy, uncomfortable about what Trump could mean for them especially if they are in a swing district. And in the Senate, you have states like Pennsylvania where Trump was today, Mark Kirk in Illinois, Kelly Ayotte in New Hampshire. They're facing very tough races this fall and how they align with Trump is becoming their key strategic decision.

JUDY WOODRUFF: We also heard — we heard Donald Trump just himself acknowledge in the last day or so that he's having problems in some states, in some of these important swing states like Ohio, like Florida, but even in a reliably Republican state like Utah.

What is that telling you, somebody who's been covering politics for some time, and what does it say to Republicans who are watching this race so closely?

ROBERT COSTA: Utah is a particularly case.

You have a new presidential candidate, an independent conservative, Evan McMullin, come from Utah. Temperamentally, the Mormon population of Utah doesn't always fit with Donald Trump. They really like Donald Trump, according to most polls. Some evangelical communities, you see Hillary Clinton, the former secretary of state, she is gaining in a state like Georgia.

Trump is trying to adjust to a general election. He's been so rough and tumble for so long, throwing punches, that it turns some swing voters off. But according to my sources in the Trump campaign, Trump is adamant that he will not change, that he wants to continue to run a campaign from the gut, on his instincts.

JUDY WOODRUFF: And what does that mean, Robert? Does that mean we can expect to hear comments like the ones in the last few days, the Second Amendment comment that some people took to mean he was threatening Hillary Clinton, and then more recently this comment that Hillary Clinton and President Clinton founded ISIS?

ROBERT COSTA: That's always the peril Trump finds himself in as a novice first-time national candidate.

He likes to be the outsider, someone who's brash and bold in his mind, but he takes risks in his some of his comments by being out there a little bit. The party hopes that he can control some more of his incendiary remarks, but still have that outsider appeal, which they think is really Trump's really only path to the White House, to make these swing voters and working-class voters who are disengaged with the system feel like they maybe have a candidate for themselves.

JUDY WOODRUFF: And, Robert, we have seen more — or at least a number of prominent Republicans like Senator Susan Collins of Maine come out and say they couldn't support Donald Trump. There was a letter this week by former foreign policy experts in the Republican Party. Then yet another letter went to the RNC from Republicans saying, we don't want you to spend as much money on Donald Trump, we want you to spend money on these other races.

Is this the kind of thing that the party leadership has to worry about or can they just ignore it all?

ROBERT COSTA: Oh, they're not ignoring it at all, Judy, because one of the things Trump is facing is, he doesn't have an institutional history within the Republican Party.

He doesn't have the relationships going back years that have sustained other nominees in past cycles when they have had a patch of rough poll numbers. A lot of Republicans now on Capitol Hill and elsewhere, they're saying, if Trump is going to lose the general election, in our view, maybe it's time to walk away, walk away in a full way, don't even have money going from major donors to the nominee, put it to those down-ballot race that are more vulnerable.

But Trump insists that the RNC is still going to work with him and Priebus was there today, but this is all happening, these conversations are circulating within the party that maybe Trump isn't going to win and things have to be done.

JUDY WOODRUFF: All right, Robert Costa with The Washington Post, we thank you very much.

ROBERT COSTA: Thank you.