KELLY MCEVERS, HOST:
After the wins for Donald Trump began rolling in last night, he held a news conference. He said his candidacy is expanding the party.
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DONALD TRUMP: That hasn't happened to the Republican Party in many, many decades, so I think we're going to be more inclusive. I think we're going to be more unified. And I think we're going to be a much bigger party. And I think we're going to win in November.
MCEVERS: But Trump's leading rivals, Senators Ted Cruz and Marco Rubio, show no signs of dropping out.
AUDIE CORNISH, HOST:
New York Republican Chris Collins was the first congressman to endorse Donald Trump, and he joins us now. Welcome to the program.
CHRIS COLLINS: Audie, I'm happy to be with you.
CORNISH: So people look at Donald Trump's campaign, and they say the Republican Party is changing. If so, into what?
COLLINS: Well, there is no question, Audie, that the base has been expanding. The energy behind Mr. Trump is just off the charts. This is a rank and file movement that you're seeing, with massive turnouts from New Hampshire down to Mississippi, Alabama. I mean, his supporters are representative of the entire country.
CORNISH: Now, your fellow House Republicans, Scott Rigell of Virginia, he's on elsewhere in our program. But he told us that he finds it unfathomable that Trump could lead the party after some troubling missteps. And here he is describing with those missteps are.
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SCOTT RIGELL: When he mocks the disabled, when he really badly stumbles when asked about David Duke and the KKK, when he says that he admires Putin and then quotes the fascist dictator Mussolini.
CORNISH: Those are deal-breakers for Rep. Rigell. Is his approach alienating other party faithful and potentially independent voters?
COLLINS: Audie, I know that Donald Trump is not a racist. He disavowed David Duke. He disavowed the KKK. He did it emphatically. He did it a number of times. And if he had a problem with the earpiece, which he did...
CORNISH: But even, like, House Speaker Ryan didn't seem that convinced with that explanation.
COLLINS: To me, Donald Trump, right from - I mean, this goes back many months ago - he was disavowing the KKK and David Duke. So I think, to some extent, it's a red herring that people keep bringing something up he's been absolutely clear on. He is not a racist. You know, at some point, people need to stop beating a dead horse here. That's just not the issue.
CORNISH: What's your message to your colleagues, to supporters who are still backing Ted Cruz or Marco Rubio, still holding out hope that they can come from behind and/or challenge Trump at a convention?
COLLINS: My message to my fellow members here has been the math is in Donald Trump's favor come March 15 with Florida and Ohio winner take all. And it's time then for our party to unite around the Republican who will be challenging Hillary Clinton in November. We have to defeat Hillary Clinton, or the country we know will not be the country our children and grandchildren grow up in.
CORNISH: It sounds like your message is get over it and get in line.
COLLINS: That's exactly my message. He is going to be our candidate. We need to get behind him. We need to defeat Hillary Clinton.
CORNISH: Congressman Collins, when did you make this turn yourself? Was there a moment where you had to kind of get over it and embrace Donald Trump?
COLLINS: For me, Audie, it was very simple. I've said all along we need a chief executive, not a chief politician in the White House.
CORNISH: But you were a supporter for Jeb Bush before.
COLLINS: Correct. He was the chief executive of Florida. Mr. Trump is a chief executive in the private setting of a very complex business. And we don't need a legislator in the White House. We've seen what seven-and-a-half years of Barack Obama has resulted in.
CORNISH: But you're making it sound like a seamless transition. There's a lot of handwringing going on by others.
COLLINS: No, it was very easy for me. We need a chief executive in the White House. And when Jeb Bush pulled out, I looked, and there were three people standing there, only one that is a chief executive in Donald Trump. He's a born leader. He's got the right view of the main issues, whether it's border security, national defense, immigration or getting our jobs back, so a very easy transmission for me.
CORNISH: That's New York Republican Congressman Chris Collins. Thank you so much for speaking with us.
COLLINS: OK, Audie, anytime. Transcript provided by NPR, Copyright NPR.