Transcript for Mark Halperin: Ben Carson 'A Better Fit' for Iowa Voters Than Donald Trump
Moving on to republicans right now, the big story this week, Ben Carson going to the lead in Iowa. Mark, the poll with Des Moines register showing him in front. I want to put this up right now, it shows that Carson's controversial comments, it's helping them. 81% comparative of Obama care to sla slavely is 81 .. Look, George, we know for a fact that those comments are unpopular with the east coast media. They're popular with partisan supporters. And republicans generally. We know for a fact that Carson is not only ahead in Iowa but a better fit for Iowa than Donald Trump. We also know that the other campaigns, including the trump campaign, long term, doesn't worry about Carson as a threat for the nomination. Now, all those things could be right, but they could be wrong in the last case, which is the Carson campaign feels they can raise money. But for now, there's a lot of people underestimating Ben Carson. Their view is, trump, bush, others don't believe that Carson is a long-term threat. Skwlon, not worried long term about Ben Carson. But those comments about seventh-day adventist. He may be right that he didn't criticize him, but he's raising it for a reason. Yes, well, there's no doubt he's raising it for a reason. Two reasons to say, I don't know. Donald Trump on the air this morning with you said, I don't know about that. Another way to hear that was I don't know about that. I just don't know he's on very strong footing, especially here in Iowa, trying to get into a religious battle with Ben Carson. Lot of Iowa voters who have some questions about the authenticity of Donald Trump's religious commitments. Jon Karl, we'll see if he continues to rise after that. He won't get his apology. As for trump, this was a big milestone. Trump is no longer the front-runner in at least two polls. But trump is still leading in roughly 49 other states. Ana Navarro, you're a big supporter of Jeb bush, you raised money for Jeb bush, we saw this week he had to cut his payroll. I was very happy to see that, I was very happy to see -- You were happy? Yes, I was. They needed course correction. Look, I was with McCain when he hit rock bottom. He was nowhere in the polls, he was nowhere, period, he was declared dead politically. He was able to rise from the ashes. They have to acknowledge the political landscape is completely different. But there's a big difference, isn't there a big difference from McCain when he dropped out, most republicans still thought pretty well of him, but in these polls, Jeb bush still has very deep unfavorables, doesn't he? The question is, who will definitely not support? He's at the top. When he got into this race, his biggest liability was his name. That he was a bush. That may be the only thing that's keeping his campaign alive. Where his fund-raising is coming. His campaign is struggling. He's got the name. That's what he has left. But what there is right now, there's a recognition that needs to be a turnaround, not when it comes to structure but branding. You got a candidate who's committed to continue working. He told me I'm going to continue to work harder. He's got a lot of fight in him. As long as he keeps fighting, people like me will stand by his side. Meanwhile, the candidate who seems in the catbird seat, Marco Rubio, he now has the best chance of getting the nomination. Look at this one from predictwise. 35% for Rubio. Still 20% for Jeb bush. 17% for Donald Trump. Jennifer Granholm, is Marco Rubio the toughest candidate for Hillary Clinton or whichever democrat gets the nomination? I don't know if he's the toughest because he's one of the most extreme. For example, he doesn't agree with a woman's right to choose in even in the case of rape or incest. He doesn't believe in same-sex marriage, where most of the population believes we shouldn't be shutting down the government to defund planned parenthood. He's a new generation but with old ideas. If you're a new generation and you got ideas that are back in the '50s -- George, I remember in 2008, hoping and praying Barack Obama would be the nominee, I thought he would be easier to beat than Hillary Clinton. Boy, we were wrong. Marco would be a great contrast. In age and energy level. He's hispanic. He has an amazing ability to engage with an audience, to emote when he speaks. So, yes, he would be a challenge. Mark Halperin, anyone else poised to make a move? In that second tier as a republican candidate. Ted Cruz has a real good chance. Second, third best chance to be the republican nominee, strong in Iowa, strong in both grassroots fund-raising and big donations. But the real open lane is the establishment lane. Jeb bush, John kasich, maybe Chris Christie also have a chance, because no one in the establishment lane is moving up the way Carson and Cruz are -- John, the big question this time, you go back 50 years, is that pattern going to hold or is this year different? Well, George, on the basis of everything we have seen over the course of the last ten months which has been totally surprising, an historical precedent, it looks like this time could be different and the republican party has changed sufficiently, that the nonestablished wing may have the upper hand. We just don't know. If you look at the strength of Cruz, Carson and trump together, you would have to say right now, it's more likely that one of those three guys get the nominee than anyone else. The good news is they have been wrong. I only hope John is wrong now. One thing that I say, when you look at the polling, who is your second choice, Marco Rubio is consistently at the top. Second choice for most republicans. You made some news today in getting Donald Trump to admit that he is considering eliminating medicare in favor of the -- Go ahead. We got to go. Before we do, we're going to run out of time. Our powerhouse puzzler,
This transcript has been automatically generated and may not be 100% accurate.