Washington (CNN)Republican presidential candidates sought to cement -- or improve -- their standings in a debate Tuesday night that comes less than two months before the first votes of the election season are cast.
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CNN Republican debate: Winners and losers
The CNN debate in Las Vegas marked the first time the White House hopefuls shared a stage since terror attacks in Paris and San Bernardino, California. They flashed their foreign policy credentials and targeted each others' weaknesses in the debate that lasted more than two hours and focused exclusively on foreign policy and national security.
The result of the showdown: Some winners, and some losers.
The former Florida governor walked onto the CNN debate stage on Tuesday facing a make-or-break moment for his struggling campaign.
Polling at about 3% nationally, pundits had low expectations for Bush. But he was able to make the most of the moment and his performance will likely reassure skittish donors and supporters who have doubted him.
Appearing confident, Bush repeatedly engaged front-runner Donald Trump and at times flustered the real estate mogul. Unlike previous debates where he has backed off, Bush didn't relent in the face of Trump's return fire.
"If you think this is tough and you're not being treated fairly, imagine what it's going to be like dealing with Putin or dealing with President Xi or dealing with the Islamic terrorism that exists," Bush said over Trump's persistent interruptions.
CNN political commentator Michael Smerconish said after the debate that Bush "turned in a strong performance" with his ability to repeatedly needle Trump.
"Jeb had a good night," he said.
The tea party favorite avoided a cage match with front-runner Donald Trump in favor of a sparring match with Rubio.
Cruz and Trump have largely avoided skirmishes on the campaign trail but that ended in recent days as the Texas senator's standing improves in Iowa.
Former Mitt Romney aide and current CNN political commentator Kevin Madden said Cruz's strategy of avoiding confrontation on the debate stage was effective.
"I think the strategy Cruz has is working, bear hugging Donald Trump. I think Donald Trump does not feel antagonized," he said.
While Cruz didn't give viewers anything like the fiery and memorable soundbites his supporters savored in the last debate, the Texas senator gave a strong performance sure to please his base. And by taking aim at -- and holding his ground against -- Rubio, Cruz did nothing to stall his burgeoning momentum.
Sen. Marco Rubio delivered a front-runner's performance, as he parried blows from all sides in the crowded field.
Rubio worked to stay above the fray of candidates, focusing on showing off his in-depth understanding of foreign policy and deflecting the attacks his competitors hurled his way. The Florida senator, though engaged in heated exchanges with Cruz and Rand Paul at times, mostly sought to flex his hawkish national security positions rather than attack his competitors.
When prompted to address Trump's proposal to bar foreign Muslims from entering the U.S. -- which Rubio opposes -- or to address his recent criticism of Cruz, Rubio didn't bite. Instead, the Florida senator used the opportunity to speak at length about foreign policy concerns and his own proposals -- or to attacking President Barack Obama's administration.
As the real estate mogul has done in recent debates, Donald Trump offered a measured performance stylistically different from the fiery stump speeches he delivers at rallies to supporters. And the typically confrontational businessman largely avoided tangling with his fellow contenders.
It was a safe performance for Trump, but it's one that certainly won't deter his supporters and won't do anything to hurt his front-runner status.
CNN political commentator David Axelrod, a former top Obama adviser, said that while Trump didn't meet the bar on facts and "linear thinking," he was "in character."
"I think he probably did what he needed to do," Axelrod said, adding that it didn't hurt that few of the candidates to Trump's right and left were "eager to tangle" with the front-runner.
New Jersey Gov. Chris Christie's goal on Tuesday was to try and further his recent rise in stock in the early primary state of New Hampshire, where talk of national security has boosted the former federal prosecutor.
Christie managed to poke at the three senators in the race by lamenting the tit-for-tat debates Cruz, Rubio and Paul engaged in. The governor continued to play to his executive experience and his prosecutions of terrorism cases as a U.S. attorney.
In one of his strongest moments, Christie slammed the senators on stage as "people who've never had to make a consequential decision in an executive position" and proclaimed that voters were looking for "a president who actually knows what they're doing."
CNN political commentator Jeffrey Lord, a Trump supporter, noted that like Trump, Christie "was delivering a message" on stage rather than getting too "in the weeds" on policy.
Ben Carson said it himself on Tuesday heading into the last debate of the year: He needed to prove his national security credentials to reassure voters fleeing his campaign amid rising concerns over terrorism.
But the retired neurosurgeon faltered on that front -- offering little in the way of assuaging those concerns, which are believed to have contributed to Carson's fall from his position near the top of the polls in Iowa and nationally.
Instead, Carson offered vague and meandering responses to specific foreign policy questions, complained about the time allotted to him and declined when asked whether he sided with Cruz or Rubio in the debate over National Security Agency data collection.
Carly Fiorina still looked and sounded like a top debater on stage Tuesday night, but a closer look shows that the former Hewlett-Packard CEO is offering little to voters that they haven't already heard.
In short, Fiorina's shtick is getting old.
And several of Fiorina's attempts to elbow her way into the debate as other candidates were speaking -- a tactic that has worked for her in the past -- didn't help her during this performance.
Her strongest moments, though, came when she touted her experience as a tech executive as a way to highlight the need for the private sector to boost the federal government's counter-terrorism efforts.
Kasich faced a similar problem as Fiorina -- he didn't offer anything new that would jumpstart his candidacy.
Kasich tried his best once again to play the role of the adult in the room, calling out Trump for unserious proposals and questioning other candidates' assessment of the situation in Syria, for example.
But Kasich failed to snag himself a moment.
The libertarian senator from Kentucky showed he was in a fighting mood from the outset: jabbing at Trump and Rubio in his opening statement
Unfortunately for Paul, nobody wanted to tangle with him.
Even Trump -- who rarely resists an opportunity to needle his competitors -- didn't take the bait when Paul hit him at several points in the debate.
"Marco can't have it both ways," Paul said, attacking Rubio on immigration. "He wants to be this I'm great and strong on national defense, but he's the weakest of all the candidates on immigration."
But Rubio didn't hit back, simply thanking Paul for giving him another 30 seconds of talking time -- afforded to any candidate called out by one of his opponents -- and using it to lay out his position.
While Paul made his case against the neoconservative ideology coursing through the arteries of the Republican Party, he was effectively shut out by the overwhelming opposition to his foreign policy views present on stage.