MANCHESTER, New Hampshire — With several candidates facing make-or-break votes in New Hampshire, Saturday's debate was filled with fireworks. The biggest one landed right on top of Marco Rubio early in the night and made for the most dramatic and talked-about moment.
Here are four takeaways from what could prove to be the most important Republican debate yet.
Christie gets the best of Rubio
Candidates have attacked Rubio plenty in the past over his lack of experience, missed votes, and shifting positions, but the Florida senator has rebutted them effectively at every turn with disciplined, carefully planned, perfectly delivered responses.
New Jersey Gov. Chris Christie's innovation was to break the fourth wall and tell the audience that Rubio's smooth answers were themselves a dangerous liability.
The setup came in an exchange over legislative versus executive experience. Christie argued Obama's limited résumé mirrored Rubio's own.
"Let's dispel with this fiction that Barack Obama doesn't know what he's doing," Rubio said. "He knows exactly what he's doing."
That's when the fun began.
"That's what Washington, D.C., does: The drive-by shot at the beginning with incorrect and incomplete information and then the memorized 25-second speech," Christie said.
Rubio, walking right into a trap, responded by doing exactly what Christie predicted — he attacked him over his handling of a recent snowstorm then repeated the same talking point again: "This notion that Barack Obama doesn't know what he's doing is just not true. He knows exactly what he's doing."
Christie could barely contain his glee. "There it is! There it is! The memorized 25-second speech!" he said as Rubio tried to press on with his point.
It was a brutal moment that hung over all of Rubio's subsequent answers, which improved throughout the night but also included more variations on the same line about Obama's competence and intentions.
It's also exactly the sort of attack one could imagine Hillary Clinton, whose biggest strength is her policy depth, leveling in a general election debate. For a candidate whose biggest argument is electability, that's a troubling idea to have floating around Rubio.
The governors' last stand
Christie's motive for going after Rubio was obvious. He, former Florida Gov. Jeb Bush and Ohio Gov. John Kasich all are on the verge of being swept out of the race if Rubio performs strongly on Tuesday and consolidates the so-called "establishment" lane.
With their backs to the wall, the three governors entered into a non-aggression pact. Kasich and Christie lightly argued about their respective job records, but then Christie even went out of his way to praise his rival Kasich, saying he said did "a very good job" as governor.
This détente freed up Kasich to talk about his upbeat message of bipartisan cooperation, Christie to keep the heat on Rubio, and Bush to tangle with Trump uninterrupted over eminent domain. All three likely left the debate feeling good.
The good news for Rubio is that if he can just make it past Tuesday with a decent second place showing, he might never have to face those three in a debate ever again.
"Every other campaign said before this debate started that they had one singular goal tonight, which was to take out Marco Rubio," Rubio strategist Todd Harris told reporters. "They threw their best shots and they didn't do it."
Cruz gets personal
Cruz has been described as a lot of things over the campaign, but soulful and empathetic is usually not one of them. But he showed a new human side in front of a national TV audience with a devastating family story that connected to a major issue in New Hampshire: drug addiction.
"This is a problem, for me, I understand firsthand," Cruz said, describing how his half-sister fell into drugs, and recounting how he and his father searched for her in a crackhouse hoping to bring her back from the brink. Cruz said the episode showed the importance of securing the border to keep drugs out.
Other candidates have talked about drugs in personal terms on the trail, with Christie telling audiences about a friend's fatal spiral into addiction, and Bush recalling his daughter's struggles with drug abuse.
Cruz has usually been more focused on his ideas and message than the rest of the field, making it all the more jarring when he followed with a tragic story of his own.
Trump plays the front-runner
Rubio was the clear center of attention in this debate, and Trump, who is leading New Hampshire polls by double digits, seemed content to let things stay that way.
Trump usually thrives on conflict, but the only notable one there was between Bush over eminent domain, where Bush brought up a case where Trump tried to sue an elderly widow in order to buy out her property and build parking spaces for a casino.
"He wants to be a tough guy," a bemused Trump said.
"How tough is it to take property from an elderly woman?" Bush responded.
Still, Trump got his usual lines out about building a wall and confronting China over trade and this time its relationship with North Korea, where the field responded to a question about how to handle a reported missile test by the country.
His Middle East foreign policy answers were a mess — he careened between criticizing the Iraq War for "destabilizing" the region and then calling for the U.S. to take the region's oil — but that was nothing new.
Trump also took a question on health care, an area where rivals have accused him of advocating too big a role for government, but his position was too vague to criticize in either direction. "We're going to take care of people who are dying on the street," Trump said.