[Blitzer:] Tonight, Donald Trump is calling on several of his Republican rivals to simply drop out of the race. He says the candidates who are doing poorly in the polls, who are getting 1 or 2 percent, they are simply, he says, wasting their time. This as Trump's own poll numbers, they're softening a little bit. Dr. Ben Carson is emerging as the new frontrunner in at least two national polls among Republicans. Our political reporter, Sara Murray, is covering the Republican race for us. Sara, you were there at Trump's news conference today. Tell our viewers how it went.
[Sara Murray, Cnn Political Correspondent:] I was. And in addition to touting his new book out today, Donald Trump also had some sharp words for his rivals, everyone from Marco Rubio, Jeb Bush and even Ben Carson, the latest Republican frontrunner.
[Murray:] Ben Carson tightening his grip on his frontrunner status. Twenty-nine percent of GOP voters nationwide support Carson in the latest NBC News"Wall Street Journal" poll, a six-point lead over Donald Trump.
[Dr. Ben Carson , Presidential Candidate:] Our strength is in our unity, and we need to stop listening to the purveyors of division, who are trying to make us think that there's a war going on with everything.
[Murray:] Taken together, the two outsiders dominate the field, drawing 52 percent support.
[Donald Trump , Presidential Candidate:] If you add Ben and myself, we're beating everybody by a lot. That seems to be the big story.
[Carson:] I've continued to do what I've been doing.
[Murray:] Carson's gains coming as he travels the country promoting his book. Not to be outdone, Trump celebrated his own book release today and took a swipe at the man on top of the polls.
[Trump:] He's a different kind of a person. My book is very hard- hitting. You look at Ben, he's very weak on immigration and he wants to get rid of Medicare.
[Murray:] Training his fire on another rival, Trump predicted Jeb Bush doesn't have what it takes to win the White House.
[Trump:] Can Jeb make a comeback? I think it's going to be very hard.
[Murray:] And said it's time for some of his GOP opponents to give up the fight. [on camera]: Do you think it's time for some of the Republicans in the field to drop out?
[Trump:] If a person's been campaigning for four or five months and they're at zero or 1 or 2 percent, they should get out.
[Unidentified Female:] I'm going to go back, if I can...
[Murray:] With the candidates now at odds with each other over how to move forward with their debates, President Obama is mocking the entire field.
[Barack Obama, President Of The United States:] If you can't handle those guys? You know, then I don't think the Chinese and the Russians are going to be too worried about you.
[Murray:] While Trump complains it's the Democrats that have it easy.
[Trump:] Hillary Clinton, no tough questions. I mean, why didn't they ask about Bill? Why didn't they ask about all of the different things? Hillary had only softballs all night long. It was like this: "Here, Hillary, hit this one over the park."
[Murray:] Now, it's worth remembering that in 2007, President Obama, Hillary Clinton and John Edwards all decided to skip a debate that was hosted by FOX News. So, it's clear that complaints about debates really do work across the aisle Wolf.
[Blitzer:] They certainly do. All right. Thanks very much, Sara, for that report. Let's bring in senior political reporter Nia-Malika Henderson; our Republican strategist, our CNN political commentator Ana Navarro, she's a Jeb Bush supporter, also a friend, by the way, of Marco Rubio; and our CNN senior political analyst, Ron Brownstein, he's the editorial director of "The National Journal." And Sara was right, Ron. You and I remember, President Obama back in 2007, when he was running for the Democratic nomination, he didn't want to do a debate on FOX News either.
[Ron Brownstein, Cnn Senior Political Analyst:] Yes, and in fact, there was a big push from a liberal group in the Democratic coalition to kind of ostracize FOX. It was much about kind of separating FOX as it was kind of keeping the candidates away from the FOX anchors. Look, what the president said was a little unfair in that sense, but equally unfair was the underlying accusation that he was responding to, the idea that if we had a president with more backbone, that that by itself would change the way Putin behaves. Republicans think George W. Bush has a lot of backbone, but Putin invaded Georgia during his presidency. So, I think, you know, there's a little bit of a back-and-forth here. The larger point, though, I think, Wolf, is that this president has a lot at stake in the 2016 election. Every outgoing president has a big stake in the elections that succeed him, but if you think how Obama has been pursuing his goals in the second term, he's largely given up on working through Congress, he's pushed the boundaries on executive authority on climate, immigration, education and health care reform, and that means that all that he's much of what he's accomplished is pretty easy to reverse through the stroke of a pen of the next president. He wants to make sure a Democrat is controlling that pen in 2017.
[Blitzer:] And Donald Trump, Nia, he came out swinging today against several of his rivals, including Dr. Ben Carson, for that matter. I think he sensed the fact that a "New York Times" poll, "The Wall Street journal" poll nationally among Republicans, Carson is now number one, Trump is number two. He doesn't like to be number two.
[Nia-malika Henderson, Cnn Senior Political Reporter:] That's right.
[Blitzer:] So, presumably, he's going to get tougher.
[Henderson:] That's right. And he's had trouble sort of figuring out what line of attack to launch against Ben Carson. Today, he talked about immigration reform. In the past, he's talked about him having a wrong temperament and low energy. He's also talked about his faith. He's a Seventh Day Adventist, Carson is. All of those, especially, the one, the attack on religion didn't work. So, he's got to figure out what he needs to do with Donald Trump. Part of the problem is that Donald Trump has lower approval ratings than Ben Carson. So, I think that affects what he's going to do. He doesn't want to come across as sort of Mr. Mean Guy when it comes to attacking Ben Carson, because a lot of people see him as Mr. Nice Guy. So, I think that's a problem for Donald Trump. He's not used to being in second place. He's in second place not nationally, but in Iowa as well, which matters more at this point than those national polls.
[Blitzer:] And, Ana, your guy, Jeb Bush, in the NBC"Wall Street Journal" poll, he's not doing that great. Carson, we had him at 29 percent, Trump at 23 percent, Marco Rubio 11 percent, Ted Cruz 10 percent, Jeb Bush only 8 percent in this poll. For a guy who was once a front-runner, he's got a lot of work to do now, doesn't he?
[Ana Navarro, Cnn Political Commentator:] He's got a lot of work to do. I think he's got to reset, rebrand, reboot, refocus, re- everything. And, you know, is it possible? Yes, I saw John McCain rise from the ashes of a campaign and defy the political obituaries that were written about him and go on to win the nomination. I know that Jeb is committed to it. I know he's got the humility, the discipline. I know he's got the backbone to do it. Now he just has to do it. I think, Wolf, the expectations on him right now are so low that, frankly, if he goes out on the debate stage in a week and shows a pulse, hits a triple, it but he has got to do it. He can't have another lackluster debate performance. And I think Jeb understands that. Jeb has got the, you know, wherewithal to hear the chatter around him, to hear those writing him, e-mailing him, talking to him. And I think he understands that he has got to project more forcefully than he has been doing in the past.
[Blitzer:] He certainly does. And he knows that as he himself says. All right. Thanks very much, Ana, for that. Nia, Ron, guys, appreciate it. By the way, Donald Trump will be interviewed on CNN's "NEW DAY" tomorrow. Tune in during the 7:00 a.m. Eastern hour. Donald Trump on CNN's "NEW DAY." Just ahead, the newest information coming in to CNN about that Russian plane crash and the possible cause. Plus, does Jeb Bush feel as though he's disappointing his famous family as his presidential campaign stalls? Stand by for more of his interview with CNN's Jamie Gangel.