Why Rubio won

This article originally appeared in Slate.

There's a theory in presidential politics that if you're a young senator facing questions about your inexperience and ability to lead, you can create an aura of leadership through successful campaign moments that can substitute for actual experience. John Kennedy did it by winning the Wisconsin and West Virginia primaries, and Barack Obama did it in 2008 by defeating Hillary Clinton. Sen. Marco Rubio did some of this in his third GOP debate.

So far Rubio has had strong but careful debates, but at the Boulder, Colorado venue sponsored by CNBC he upped his game. There were plenty of strong moments for almost all the candidates not named Jeb Bush, but what made Rubio's moments so useful for him was that they combined three things: They were well-timed, they shored up his weaknesses, and they came as his rising poll numbers and the vulnerabilities in his rivals' polling are creating a moment for him.

Rubio can credit Jeb Bush with the first moment. When Rubio was asked about skipping out on so many Senate votes, he parried the question by attacking the newspaper that wrote an editorial asking him to resign. Standard stuff and pretty predictable. But then Bush jumped in and said that as a constituent he thought Rubio should work for all six years, and compared Rubio's lack of industry in the Senate to a French workweek. You could feel the clamshell packaging come off the attack it felt so store-bought and ready-made.

Rubio responded with his own riposte. "I don't ever remember you complaining about John McCain's vote record," he said, noting that Bush had recently compared his campaign to McCain's 2008 comeback effort. "The only reason why you're doing it now is because we're running for the same position and someone has convinced you that attacking me is going to help you." That response showed he could go toe-to-toe. Rubio is in a direct competition with Bush and he won that round. Missing Senate votes in a campaign where non-politicians are at the top is not a problem. A bigger challenge for Rubio is the lack of leadership and callow youth problem, and being able to best Bush in a moment that will be passed around on social media helps with that.

Toughness is hard to show when you can't point to a job where you've had to make tough calls, but while Bush's resume has prepared him for the kinds of leadership challenges a president will face, to voters, that exchange makes it look like Rubio is the more commanding one. It was the kind of flourish Bush needed to show in this debate. Instead, Rubio showed it. (It was that kind of night for Bush, and he's now going to have to endure days of suggestions that he should replace the exclamation point with a period and end his campaign.)

Rubio also took on the moderators, turning a question about his personal finances into a paean to his humble roots. Later he said the press was a super PAC for Hillary Clinton's campaign, complaining that the conclusions from pundits about her Benghazi testimony were too favorable. It was a great line and well received by the audience. He seemed to have those kinds of lines at every turn. "My mother's on Medicare and Social Security; I'm against anything that's bad for my Mom."

This is theater review, but that's what these debates are as political events. Sen. Ted Cruz, Donald Trump, and Ben Carson are all going to fight for the same voters. They all had good nights. Carson and Cruz won big applause for attacking the moderators. When the audience reacted to a moderator's question by groaning, Carson said, "they know," which should be his new campaign slogan. But there were no fireworks between those candidates, which also helped Rubio. He wasn't overshadowed by the Trump show or the expected Trump-on-Carson action.

Those three candidates are going to duke it out for the die-hard voters in the grassroots. Whoever wins in that portion of the race will face a candidate from the crop of remaining ones. Rubio was already leading that group, but just barely. Even though Gov. John Kasich made an impassioned plea for sanity, calling on his party to reject the fantasy plans of Carson and Trump, and Gov. Chris Christie gave several strong answers, it was Rubio whose answers, coupled with the lift he was already feeling, did the most for his candidacy. Now he can expect the other candidates to love him accordingly.