ROBERT SIEGEL, HOST:
Now a Republican, Sen. Jeff Flake of Arizona, who has expressed misgivings about some of Donald Trump's positions. And, like other Republicans who've been Trump detractors, he now faces a decision - endorse a Republican ticket led by Donald Trump or withhold that endorsement and break with his own party over it.
Sen. Flake, thanks for joining us once again.
JEFF FLAKE: Hey. Thanks for having me on.
SIEGEL: So what are you going to do?
FLAKE: You know, I don't know. I'm still in the first stage of grief, denial, I guess, at this point. But got to move past it and we'll see.
SIEGEL: Well, in the past, you've cited Donald Trump's proposal to ban Muslims from entering the country and his proposal to build a wall and make the Mexicans pay for it. You describe that as not the GOP's best foot forward. If he continues to advocate those policies, can you support him?
FLAKE: I can't see how I can if he continues to advocate those policies. A ban on Muslims - a religious test for people entering the country - I cannot see support for a Republican nominee who would do that. He may well back away. I certainly hope he does.
SIEGEL: What if there's, you know, a wall paid for by Mexico in the GOP platform at the convention? Is that unacceptable to you?
FLAKE: Yeah, I can't imagine you're going to get that. I mean, the platform is not a document that we can refer back to on a daily basis - the Senate or the House - so I'm not sure that the platform and what's in it is going to move anybody's endorsement or nonendorsement of Trump. But I sure hope that we don't do something silly like that.
SIEGEL: There is another set of problems that many have with Donald Trump, the story he told about Muslims celebrating in New Jersey on 9/11, something that no one else could confirm and many denied. Yesterday citing a National Enquirer story linking Ted Cruz's father to the JFK assassination, did you see problems with Trump's judgment that go beyond what his particular positions might be?
FLAKE: Clearly, yes. To start it all for years, he was a birther, still is as far as I know, somebody who believes that the president was not born here but rather in Kenya. And that does go to his judgment. So that is very troubling to find out the conspiracy theories like the - you know, about Ted Cruz's father. It's not just troubling; it's extremely mean-spirited as well.
SIEGEL: What do you make of the idea that somehow there now can be a pivot and that all of the past - what will be less than prologue - a new presidential figure will emerge and that's the person whom you should judge, not the Donald Trump of the primary season or years past.
FLAKE: Well, if there's ever a case of hoping that a candidate doesn't keep his campaign promises, I guess this is one. I don't know how malleable he will be or if he will take different positions, but I hope that he does. But we just don't know. We don't know.
SIEGEL: Would acts of omission be sufficient or must there be some acts of commission, that is public retractions of certain positions?
FLAKE: Well, there's a long way until November and he'll be given the opportunity, I'm sure, to address these issues. So I can't imagine him being able to just not comment.
SIEGEL: What did you think of that comment we heard a moment ago from Mr. Keeling, the Trump supporter from California who said that, you know, politicians live in little bubbles? He said they're concerned about petty things, their donors and getting re-elected. Trump has greater life experience. What do you say to him?
FLAKE: Well, that's right on a number of levels. He probably does have a lot of experiences, that those of us who've been in public office for a while haven't had. Having said that, there are certain things that regardless of what background you have, if you believe that there should be a religious test for people to come to the country, that ought to be rejected. I can't imagine supporting somebody who continues to hold that position.
SIEGEL: Well, Sen. Flake, thanks for talking with us today. And as you come closer to a decision, we'd love to hear from you.
FLAKE: Thank you. You will.
SIEGEL: That's Jeff Flake, a Republican senator of Arizona. Transcript provided by NPR, Copyright NPR.