Interview with Ben Carson's Former Campaign Manager.
BOLDUAN: It is "T" minus four weeks to the Iowa caucuses. Amid the mudslinging, today Chris Christie is putting out a very different message. Hours after telling "The Washington Post" that Rubio, quote, "can't slime his way to the White House," Christie switched gears with this new TV ad to run in New Hampshire.</s>CHRIS CHRISTIE, (R), NEW JERSEY GOVERNOR & PRESIDENTIAL CANDIDATE: Do not be fooled. Any significant division within the Republican Party leads to the same awful result, Hillary Rodham Clinton, in January of 2017, taking the oath of office as president of the United States. This country cannot afford that outcome. And thus, we Republicans have a duty, I believe, a profound, moral duty, to work together.</s>CHRISTIE: I'm Chris Christie, and I approve this message.</s>BERMAN: So it's not clear the "let's all work together" message has reached Donald Trump. He is now raising questions about the eligibility of Ted Cruz to be president because Ted Cruz was born in Canada. The question now is, what does all of this look like from the inside of the fray? Let's get a unique perspective now from Barry Bennett who, until last week, was Ben Carson's campaign manager. Barry, thanks so much for being with us.</s>BARRY BENNETT, FORMER BEN CARSON CAMPAIGN MANAGER: Hey, guys. Thanks for having me on.</s>BERMAN: So, look, Donald Trump is raising these questions. He's not out and out saying that Ted Cruz should be president, but look, he's raising the issue. He's bringing it up. Apparently over the last 24 hours just about whenever he can. So from your perspective, from seeing this from the inside, why do you think he's doing this, and do you think it will work?</s>BENNETT: Well, you know, I think that it's a legitimate issue, first of all. And if you, as Republicans, if you believe that the Democrats or Hillary Clinton and her supporters are not going to bring this up in the fall, you're foolish. Of course they will. So, you know, it's good to throw it out on the table. Let Ted Cruz practice his responses, you know, let's get -- we need more practice, showing our flaws as a party. But, you know, as we get closer and closer to Iowa, it's game day, right? This is the real thing. People are starting to go after one another. You know, there's a lot of jockeying, it seems, for fourth, fifth and sixth place which is kind of silly. Calling each other names and spending all their money going after each other, that seems silly to me. Donald Trump is sitting there at above 30 in most of the polls. And unless something, you know, horrific or tragic comes along when the establishment has been waiting on now for ten months, he's going to be our nominee. And we need to start thinking about that.</s>BOLDUAN: And so, Barry, you truck about, you say it's game on. You know, we're heading into the Iowa caucuses. You've got basically Trump and Ted Cruz now on one side. And then you've got the rest of the folks on the other side of the primary right now, and these guys are killing each other on the trail and on the airwaves. It makes me wonder, from your perspective -- you've been on the inside, just recently now on the outside -- who are you most impressed with?</s>BENNETT: Well, I mean, if you look at what's really happening out there, I mean, all you've got to do is compare the size of everyone's rallies. And that's really a demonstration of grass-roots support, right? Donald Trump is having 10,000, 12,000 people show up at rallies. A lot of these guys are having five or six people show up at their events in Iowa. There's just not a comparison. You know, the establishment can fret about it all they want, but this is the new reality.</s>BERMAN: Just to be clear, you know, this is coming from a guy until a week ago was Ben Carson's campaign manager. Barry, you just said that unless something radical changes, Donald Trump will be the nominee.</s>BENNETT: Yeah. I mean, he's sitting in a polling position -- I mean, you know, people are getting kicked off to the next debate. Some people will be kicked off to the junior table. And nobody is moving up beyond 11 percent or 12 percent, and Donald Trump stays at 30, 32, 34, 35 percent. And Chris Christie is attacking Marco Rubio. It's kind of an offense. And they're all leaving Donald Trump alone. And he's got the support out there right now. And unless something cataclysmic happens, he's going to win.</s>BOLDUAN: You know it's so interesting, Barry, hearing you say that no one's taking on Donald Trump. That was absolutely the strategy of Ben Carson.