Here are some of the biggest moments for each candidate:

Santorum, the prosecutor

Early in the debate, Santorum used a lawyer-like "trap" to nail Mitt Romney on voting rights for felons. The issue isn't exactly a hot button issue for GOP voters, but it allowed Santorum to a) look tough by hectoring Romney several times for an answer, b) catch Romney in a apparent contradiction/flip-flop and c) name drop Martin Luther King while taking a stand for black people, an issue he has been particularly shaky on. He scored points, but probably not on the issues he would have preferred.

Ron Paul was ... Ron Paul

Paul had the most trouble with the South Carolina crowd (Politico called it a "drubbing"), particularly when criticizing our approach to killing, rather than capturing terrorists. At one point, he compared Osama bin Laden hiding in Pakistan to a Chinese dissent seeking asylum in the United States, which other candidates quickly seized on. ("Utterly irrational," according to Newt Gingrich.) Of course, being the outlier is nothing new for Paul and, as usual, he didn't cave in to the crowd just to get the cheap applause lines.

Gingrich remains politically incorrect

Gingrich's big moment came in a feisty exchange with moderator Juan Williams, who asked if black Americans should be insulted by Gingrich's claims that poor kids lack work ethic and that African-Americans should "demand jobs, not food stamps." Gingrich defiantly answered no, doubling down on his "put kids to work as janitors" policy and zinging that "only elites despise making money." (A classic applause line that the home crowd ate up.) Williams was booed when he followed up by criticizing Gingirch for calling Obama "a food stamp president," another attack that he dismissed as "politically correct.") Peter Beinart of The Daily Beast said Gingrich's condescending answer to Williams shows not that he's racist, but "clueless" and living in "a cultural and intellectual bubble. A bubble called the Republican Party.

Perry caught off guard

Perry, who was largely irrelevant in the race and the debate, got tripped on a tricky foreign policy question when asked if Turkey should be kicked out of NATO. Perrry compared the country's leaders to Islamic terrorists (suggesting the answer is "yes") and questioned whether the U.S. should send them any foreign aid at all. He also took heat online for invoking murdered journalist Daniel Pearl in a defense of the Marines who were caught urinating on Iraqi corpses. Pearl's colleague John Harwood called it "irrelevant and gross." He did score points, however, for pushing Romney on his tax returns.

Romney under fire

Romney received the most pressure on two early topics: His unreleased tax returns (which he said he will "most likely" but not definitely give up as some point) and his record at Bain Captial, which has become the focal point of this race right now. On this point, it seems capitalism is in the eye of the beholder, as most of the financial reporters we follow seemed to like his answers describing how the companies that he helped shutter were in doomed industries. But it's still not clear if long explanations about the benefits of private equity in the capitalist world will play with everyday voters who just want their jobs back. (Romney also called the Gingrich documentary about him "The biggest hoax since Bigfoot," which is much easier to understand.)