DAVID GREENE, HOST:
Well, if you find personal insults entertaining, if you enjoy jokes about the human anatomy or tanning products, the 12th Republican presidential debate was probably not for you. If you like a conversation about substantive issues, maybe it was. The debate was in Miami. Florida's one of the big states voting this Tuesday. The sponsors were CNN, the Salem Media Group and The Washington Times. One of the people watching was NPR national political correspondent Mara Liasson.
MARA LIASSON, BYLINE: All of a sudden, the Republican candidates were on their best behavior. Personal insults were not exchanged. Interruptions and shouting didn't happen. It was as if the four GOP presidential hopefuls retreated to their corners, worried that they had damaged the party in their previous food fight of a debate. Donald Trump came to Miami determined to present himself as an unstoppable front-runner. And he confidently called on Republicans to unify behind him. Here he is, courtesy of CNN.
(SOUNDBITE OF ARCHIVED RECORDING)
DONALD TRUMP: We're all in this together. We're going to come up with solutions. We're going to find the answers to things. And so far, I cannot believe how civil it's been up here.
(APPLAUSE)
LIASSON: And that about summed up the evening. Trump himself was calm and serious - no lying Ted or little Marco. He didn't talk about his steaks or his water or his anatomy. In a big blow to Ted Cruz, Trump announced that today, Ben Carson would be endorsing him. Trump also said he would consider sending up to 30,000 U.S. troops to fight ISIS and that the U.S. needed to go further than waterboarding to fight terrorists.
(SOUNDBITE OF ARCHIVED RECORDING)
TRUMP: We have to obey the laws - OK, have to obey the laws. But we have to expand those laws because we have to be able to fight...
(APPLAUSE)
TRUMP: ...On at least somewhat of an equal footing, or we will never ever knock out ISIS and all of the others that are so bad. We better expand our laws, or we're being a bunch of suckers and they are laughing at us. They are laughing at us. Believe me.
(APPLAUSE)
LIASSON: Marco Rubio's support cratered after he tried to fight Trump with Trump-style insults about his spray tan and the size of his hands. So last night, Rubio returned to his original positive message, pushing back respectfully against Trump's statement that Islam hates us.
(SOUNDBITE OF ARCHIVED RECORDING)
MARCO RUBIO: I know that a lot of people find appeal in the things Donald says 'cause he says what people wish they could say. The problem is presidents can't just say anything they want. It has consequences here and around the world. I can also tell you that if you go to any national cemetery, especially Arlington, you're going to see crescent moons there. You're going to - if you go anywhere in the world, you are going to see American men and women serving us in uniform that are Muslims.
(APPLAUSE)
RUBIO: And they love America.
LIASSON: Rubio has tangled with Ted Cruz in previous debates, but last night, Cruz ignored Rubio altogether. Cruz was focused only on Trump, who is now about a hundred delegates ahead of him. But Cruz's attacks on Trump were also relatively restrained.
(SOUNDBITE OF ARCHIVED RECORDING)
TED CRUZ: The answer is not simply to yell, China bad, Muslims bad; you've got to understand the nature of the threats we're facing and how you deal with them. And yes, it is true there are millions of radical Islamic terrorists who seek to kill us. We need a president commander-in-chief focused on fighting them. And I'll tell you frankly, one concern I have with Donald is that, although his language is quite incendiary, when you look at his substantive policies on Iran, he has said that he would not rip up this Iranian nuclear deal. I think that's a mistake.
LIASSON: Trump was asked by CNN moderator Jake Tapper whether he felt any responsibility for violence at his rallies, including an incident on Wednesday where a Trump supporter sucker punched a protester. Trump's answer, without condoning the attack, seemed to blame the protesters.
(SOUNDBITE OF ARCHIVED RECORDING)
TRUMP: There is some anger. There's also great love for the country. It's a beautiful thing in many respects, but I certainly do not condone that at all, Jake.
JAKE TAPPER: Some of your critics point to quotes that you've made at these debate - at these rallies, including February 23, I'd like to punch him in the face, referring to a protester. February 27 - in the good old days they'd have ripped him out of that seat so fast. February 1 - knock the crap out of him - would you? - seriously, OK. Just knock the hell...
(APPLAUSE)
TAPPER: ...I promise you I will pay for the legal fees. I promise. I promise.
TRUMP: We have some protesters who are bad dudes. They have done bad things. They are swinging. They are really dangerous. And they get in there, and they start hitting people. And we had a couple big, strong, powerful guys doing damage to people.
LIASSON: Ted Cruz brought up something else that happens at Trump's events.
(SOUNDBITE OF ARCHIVED RECORDING)
CRUZ: At Donald's rallies recently, he's taken to asking people in the crowd to raise their hand and pledge their support to him. Now, I've got to say, to me, I think that's exactly backwards. This is a job interview. We are here pledging our support to you not the other way around.
(APPLAUSE)
LIASSON: John Kasich, whose survival in the race depends on winning his home state of Ohio on Tuesday, sounded almost apologetic when he explained why he has waged an unwavering positive campaign.
(SOUNDBITE OF ARCHIVED RECORDING)
JOHN KASICH: And I wanted to raise the bar in presidential politics so our kids can take a look at the way you can run for president, and you will someday maybe be president of the United States. You know, sometimes being positive isn't all that interesting. But it's very interesting to my family, my children and so many supporters that I meet all across the country. And I will continue to run a positive campaign.
LIASSON: Next Tuesday's winner-take-all contests in big states like Ohio and Florida will determine whether Trump is unstoppable or if he can be prevented from collecting the 1,237 delegates to win the nomination. Last night Trump said the nomination should go to the candidate with the most delegates not what he called a, quote, "artificial number." The CNN debate was one of the last chances Trump's rivals had to slow his momentum. But they didn't challenge him very strongly, as if they decided it wasn't really worth it. Mara Liasson, NPR News. Transcript provided by NPR, Copyright NPR.
