Rubio was polished, optimistic, strong on issues, from immigration to education to the economy, and never once reached out in thirst for an off-screen water bottle.
Trump was belligerent, borderline incomprehensible on issues and straight-up condescending and misogynistic when pressed by Fox's Megyn Kelly on his past repulsive comments about women.
Calling women "fat pigs," "dogs," "slobs" and worse, and saying they would look good on their knees is not a refreshing dismissal of constricting PC norms. It's gross and Kelly called him on it. Trump, who hates being called on anything, complained that Kelly wasn't being very nice to him, which of course is not her job.
After the debate, Trump complained that Kelly "behaved very badly," something an angry husband denied immediate service of his evening drink and dinner might say about his wife in the 1950s.
No GOP candidate is going to win the general election—much less against Hillary Clinton—if most women loathe him. And Trump is on his way to exactly that.
Then there were his crazy answers.
Trump said that without him the GOP would not be talking about illegal immigration. Laughable. It was a huge topic before he entered the fray.
The rest of his comments on the topic made no sense either: "This was not a subject that was on anybody's mind until I brought it up at my announcement," Trump said. "And I said, Mexico is sending. Except the reporters, because they're a very dishonest lot, generally speaking, in the world of politics, they didn't cover my statement the way I said it … The fact is, since then, many killings, murders, crime, drugs pouring across the border, are money going out and the drugs coming in. And I said we need to build a wall, and it has to be built quickly."
Pressed for evidence of his claims on murderers and rapists, Trump invoked "people" he talks to: "Border Patrol, I was at the border last week. Border Patrol, people that I deal with, that I talk to, they say this is what's happening. Because our leaders are stupid. Our politicians are stupid."
Good stuff. Contrast that with Rubio: "Let me set the record straight on a couple of things. The first is, the evidence is now clear that the majority of people coming across the border are not from Mexico. They're coming from Guatemala, El Salvador, Honduras," he said. "Those countries are the source of the people that are now coming in its majority. I also believe we need a fence. The problem is if El Chapo builds a tunnel under the fence, we have to be able to deal with that, too. And that's why you need an e-verify system and you need an entry-exit tracking system and all sorts of other things to prevent illegal immigration."
At one point, Chris Wallace asked Trump specifically what he would do about a despised Iranian general going to Russia to meet Vladimir Putin. This is what he said:
"I would be so different from what you have right now. Like, the polar opposite. We have a president who doesn't have a clue. I would say he's incompetent, but I don't want to do that because that's not nice. … But if you look at the deals we make, whether it's the nuclear deal with 24-hour periods—and by the way, before you get to the 24 hours, you have to go through a system."
If you can figure that one out you get a prize.
Rubio wasn't perfect. He struggled a bit on his position on a rape and incest exception for laws banning abortion, something anti-abortion conservatives despise. Aides later partially walked back his comments. But beyond that he was mostly brilliant, especially framing his candidacy against Hillary Clinton's.
"If I'm our nominee, how is Hillary Clinton going to lecture me about living paycheck to paycheck?" Rubio said in one of his biggest applause lines. "How is she going to lecture me about student loans? I owed over $100,000 just four years ago. If I'm our nominee, we will be the party of the future."
As for the rest of the participants, none likely moved the needle much. Jeb Bush was just OK, shaky at first then stronger as the night wore on. He's clearly rusty from over a decade out of electoral politics. But he didn't need a home run. He's fully funded and playing the long game.
Scott Walker was competent, Chris Christie was very strong on issues and mixing it up with Rand Paul. Ben Carson had some good moments. Ted Cruz was barely there. John Kasich probably helped himself with his folksy delivery and charismatic empathy.
But nobody stood out like Rubio. And nobody tanked like Trump. Will this be the moment where his sugar-high numbers start to fade? Maybe not. But that day is coming.