RENEE MONTAGNE, HOST:
The Republican presidential candidates are gathered in Las Vegas for their last chance to debate in 2015. This debate is considered especially important because voters are finally going to start voting in the Iowa caucuses on February 1. Political reporter Robert Costa of The Washington Post is in Las Vegas for the debate. And he joined us to talk more about it.
ROBERT COSTA: Good morning.
MONTAGNE: Now, tonight at the debate, Ted Cruz will be standing to the right of Donald Trump, a position he can occupy due to the fact that he has ascended in the polls to number two, behind Donald Trump. So do you expect to see these two candidates taking swipes at each other big-time?
COSTA: Donald Trump, he seems excited about the possibility. I was covering him last night right after he swooped into Vegas on his 757 Boeing plane. And he talked about Senator Cruz at a rally attended by a few thousand people. And he said, bring on the fight.
MONTAGNE: OK, so that's something to watch. Also, Jeb Bush, another candidate to keep one's eye on tonight. Do you anticipate he will try to get into the mix by making more forceful attacks on his opponents?
COSTA: Someone like Cruz, he's a real target for Trump because he's been rising in the polls in Iowa. But if you're a more mainstream Republican, a Jeb Bush, a Marco Rubio, a John Kasich, a Chris Christie, you're not so much of a target for Trump because you're behind him in the polls. He's been bragging for days now about how he's been leading nationally. And he talked much about a recent Monmouth University poll that puts him at 41 percent across Republicans nationwide. But this is a real test for those mainstream conservatives because this is the last debate for about a month. And if they want to get traction, especially in a state like New Hampshire, which is more favorable toward Republicans who are more in the party's traditional mainstream, this is their moment. And one of the key questions is how they handle the Muslim question on Trump's policy proposal to ban some of them from coming over temporarily.
MONTAGNE: Well, what do you think? Because it is expected that a key focus will be on national security. What do you expect will come out of that in terms of how these candidates play their cards?
COSTA: Most reporters and political insiders expect quite a lot of depth in this discussion on foreign policy, mostly because the moderator is Wolf Blitzer of CNN, who has some real knowledge on the issue. In post-Paris, you have seen national security issues grip the Republican electorate in much of the same way it's gripped the country. And you've seen someone like Chris Christie rise in New Hampshire touting his former experience as a federal prosecutor, going after terrorist suspects. And this is something that Trump has had to deal with. Ben Carson as well, one-time front-runner, has struggled as foreign policy's become a central issue.
MONTAGNE: Well, candidates have followed Donald Trump previously into ratcheting up their own rhetoric, as he has, about immigration and whatnot. Do you think they're going to feel the need to be as tough as he has been about the whole question of Muslims in America?
COSTA: Most Republican rivals have distanced themselves from Trump when it comes to the Muslim proposal. But they are also quite aware that many Republican voters agree with Trump's position when it comes to Muslim immigration. So huddling with some of the campaigns last night in Las Vegas, they said they'd rather avoid the issue, avoid a clash with Trump more than anything.
MONTAGNE: Right because he's still at the top of the heap.
COSTA: And most of the voters - many of the conservatives within the Republican Party agree with Trump. This is the problem for Republicans who are looking ahead to the general election. They see Trump's proposal, Trump's position, his view on Muslims and foreign policy generally as toxic for a general election audience, something that would cost Republicans votes in swing states, would be a disaster perhaps at the level of Barry Goldwater's nomination in 1964. At the same time, to win the nomination, the voters they need to win over are in many ways with Trump.
MONTAGNE: Robert Costa is a political reporter for The Washington Post joining us from Las Vegas, where the Republican debate is being held tonight. Thanks very much.
COSTA: Thank you.