With the South Carolina 2012 primary just five days away, former Massachusetts governor Mitt Romney, Texas Rep. Ron Paul, former House Speaker Newt Gingrich, former Pennsylvania senator Rick Santorum and Texas governor Rick Perry took to the stage for the first of two debates before the Jan. 21 primary.

The debate itself spanning topics ranging from border laws and the federal income tax to abstinence-only education and the killing of Osama bin Laden. But while some of the GOP candidates rose to the challenge, taking on their Republican rivals, the incumbent president and even the live audience, others floundered.

As the time to choose a GOP presidential nominee looms ever closer, every debate performance and primary victory could secure Mitt Romney's win... or clear the way for a candidate like Ron Paul or Newt Gingrich to steal the lead.

Below, read through a comprehensive breakdown of the candidates' performance in the debate last night, and how it's likely to affect their standing in the 2012 South Carolina Republican primary.

Mitt Romney: Same Old, Same Old

Romney's poll numbers in South Carolina have been consistently high over the past two weeks. Barring a shaky performance at tonight's debate, the former Massachusetts governor was expected to continue as the uncontested frontrunner.

But Romney, while he answered well and continued to push the same talking points as he has over the past few months, didn't stand out among the candidates, three of which-Gingrich, Paul and Perry-seemed on fire during the debate.

In the area of foreign policy, Romney got big cheers from the crowd when he advocated building up a strong national defense, and was very well-received when he tackled his opposition to the DREAM Act, saying he would not lose the Latino vote because he was committed to the legal immigration that made America great.

He continued to go after incumbent president Barack Obama in almost every answer, while hammering in the message that his presidency would stand for opportunity, fairness and his new catch phrase free enterprise.

Romney continues to convey a levelheaded yet personable approach to answering the moderators' questions. Yet Fox News voters viewed him as the least straightforward candidate of the bunch, as well as the one to most often dodge a tricky question.

This was especially apparent when Rick Perry went after Romney for not releasing his tax records. In a rare moment of fumbling, Romney stumbled through several answers before settling on the ambiguous half-assent. Moderators, picking up on his hesitance, returned to the tax record question several times throughout the debate, with Romney awkwardly brushing them aside each time.

In all, it was a good performance, but not particularly memorable. Romney isn't fighting for votes the way his opponents are doing, but last night's debate highlighted the return of one of Romney's weaknesses: he doesn't convey a lot of passion for the issues.

Notable Quotes:

On Bain Capital: My record is out there and I'm proud of it.

His opposition to the DREAM Act alienating Latinos: They, like all voters in this country, are interested in America being a nation of opportunity.

Rick Perry: The Sound and The Fury

Rick Perry had to make a great showing last night. After dismissing New Hampshire and focusing his sights on South Carolina, the Texas governor was still in last place.

Perry's performance at the first South Carolina 2012 primary debate was indeed one of his best, and has already made some analysts scratch their heads about where this speaker was all through the fall of 2011.

Perry made the most headway when he stuck to state's rights issues and focused on attacking President Obama. He won big applause when he went after the current administration for curtailing Texas and South Carolina and launching a war on religion, employing military terms like at war and assault to great success.

But Rick Perry remains the odd candidate out in the race, one more content to jump on others than make a clear and defined statement himself. Throughout the debate, he made either side remarks or launched outright attacks on his rivals, something Santorum and certainly Gingrich were wise enough to leave mainly off-stage.

Charging Romney to release his tax records, saying Paul should be signaled to stop talking with a gong, and trying to chip away at the same Paul's military vote might ending up hurt his targets. It does nothing to help him.

And when talk turning to foreign policy, Perry again stumbled, slowing down his answers considerably and side-stepping clear answers. At one point, he argued that Turkey is being ruled by what many would perceive to be Islamic terrorists, even though the country is still considered an important ally to the U.S.

Notable Quotes:

On Romney's Tax Records: Here's the real issue for us as Republicans. We cannot fire our nominee in September. We need to know now.

Calling the Act of Marines Urinating on a Taliban Corpse 'Despicable': Let me tell you what's utterly despicable: Cutting Danny Pearl's head off and showing the video of it. Hanging our contractors from bridges, that's utterly despicable.

Newt Gingrich: Comeback Kid

Newt Gingrich went into the South Carolina debate with significantly less support than he had in December. Once the candidate to beat in the Southern state, the former Speaker's attack on Romney's free enterprise with Bain Capital caused him to drop considerably.

But Gingrich is known for his debating skills, using an approach that treads that fine line between the appearance of nuance and the feeling of unwavering conviction beneath. To win the debate, Gingrich needed to follow Romney's lead by focusing his attacks on Obama and liberals rather than his fellow candidates, all while differentiating himself from Romney as the more passionate candidate.

It was a tough tightrope to walk, one Fox News commentators called the positive negative dance. But Gingrich did it.

Except for some digs at Rep. Ron Paul, Gingrich stood by his pledge to stay positive for almost all the debate. By the time he and Romney clashed over super-PACs, with both candidates accusing the other of having no control over their message, Gingrich had already set his, and the debate's, tone.

And that tone was firmly, but never flamboyantly, anti-liberal and anti-Obama. We actually think work is good, he said during one condemnation of the food stamp president, gesturing to his fellow candidates.

But what made Gingrich most notable in the first South Carolina debate, especially in contrast to Mitt Romney, was the straight-shooter appearance he gave when answering questions, giving sometimes-controversial answers that nonetheless packaged his message perfectly.

When Gingrich was challenged on an older statement about poorer children lacking good work ethic, Gingrich stood by his original claim. He then steered the conversation into unions, the American ethic and a reference to his daughter's work at their local church.

Proof of his sway over the crowd came when he closed his argument. He finished with the nonsensical assertion that only the elites despise earning money (perhaps a reference to the landed gentry of America?), a statement that was nonetheless met with applause and cheers. And when he tried to challenge Gingrich again, the moderator was met with a chorus of boos.

When Gingrich is on, he's the best debater in the GOP, playing to a staunchly Republican state without appearing stiff, rehearsed or overly zealous. If Gingrich can stay on, always a question with the candidate, South Carolina could end up going his way after all.

Notable Quotes:

On so-called 99ers, who receive 99 weeks of unemployment checks: 99 weeks is an associate degree!

Welfare system: More people have been put on food stamps by Barack Obama than any president in American history. I know, among the politically correct, you're not supposed to use facts that are uncomfortable.

Whether his comments on poor children's work ethic could be construed as belittling: No... I don't see that. [Big cheers from crowd]

Ron Paul: Struggling Speechmaker

South Carolina is a state that Paul must do well in to win the nomination, and it is, traditionally, one less disposed to libertarians or anyone ever considered a fringe candidate, regardless of the truth of the claim.

From 1980 on, no GOP candidate has ever won the Republican nomination without winning South Carolina first. The Southern state is tuned to look for the most electable candidate first, more so than in New Hampshire or Iowa.

At last night's debate, Ron Paul needed to step up his game against Mitt Romney, and against the prejudices that have dogged him since the beginning of the Republican primaries. He needed to outline his differences from Romney, take on the Obama administration, and present a more presidential and mainstream image during the debates.

Paul succeeded in two of those aims. He refused, as always, to be moved from his firmly held and very vocal opposition to many elements of GOP establishment thinking, at one point exclaiming: We're supposed to be conservatives! Stop spending money!

And despite a crowd cheering hardest for candidates advocating military might, Paul nabbed some cheers of his own when he faced off against Romney on the National Defense Authorization Act, arguing that it was a breach of the American judicial system.

He also received lots of positive feedback for his position on a starting federal income tax of zero and discussed his support among veterans and soldiers. He was even able to battle back into the center of the discussion after being placed (oddly, for a second place finisher) at the edge of the panel, a disadvantage many remarked on.

But Paul's weakness in last night's debate came from the same dogged adherence to his views, and his worry that his fellow candidates, the moderators and the audience members didn't understand his point.

Paul went over the clock for almost every question. At one point, commentators asserted, erroneously, that he took over thirty minutes to answer a prompt, and moderators joked at one moment about bringing a buzzer back to cut candidates off. In an attempt to convey everything he wanted to squeeze in, Paul's answers often came off as breathy, impatient or defensive.

Presidential debates often end up being much more about how the candidate is perceived than anything they said. Paul refused to tailor his belief in non-interventionism or his condemnation of the killing of bin Laden to his audience.

As a result, more of Paul's answers were met with booing and catcalling than any other candidate by a long shot, and his rivals were quick to dive in whenever the candidate stumbled.

He [bin Laden] was not a Chinese dissident, Gingrich said when Paul attempted to outline his golden rule policy for respecting state sovereignty by comparing bin Laden in Pakistan to a dissident in the U.S. The example that Paul used was utterly irrational. Gingrich and Romney then went on to spearhead the American way: you find your enemies, and you kill them. The crowd erupted in cheers.

But Ron Paul's supporters don't give up on him easily, and those watching the South Carolina 2012 debate last night are bound to know some of the candidate's speaking style and politics.

His determination to stick by his answers, no matter what the reaction, won him grudging and eventually sincere admiration among the crowd by the debate's end, with some answers he gave beginning with boos and ending with applause.

Notable Quotes:

To Moderator: I would suggest your question suggests you're very confused about my position!

Military spending versus defense spending: You consider that military spending. I consider that a waste!

Political attacks: They should be abandoned if you're not telling the truth.

Rick Santorum: Stiff Until Social Issues

But the candidate whose presidential future hung most in the balance last night was former Pennsylvania senator Rick Santorum.

After a humiliating finish in New Hampshire, Santorum needed South Carolina to prove his campaign still had juice, but he remains trailing and tied for a low second place in the primary state.

His strength as a social conservative in deep Republican territory, meanwhile, is undercut not only by competition from Perry and Gingrich but by the fact that South Carolina, despite its evangelical and conservative roots, tends to vote for more moderate candidates like Bob Doles or John McCains than hard-line conservatives like Pat Robertson or Pat Buchanan.

To best court the South Carolinian vote, Santorum needed to realize that he had already established himself as a family values candidate, and to focus instead on articulating his positions on hot-button international and economic issues like immigration law and the federal income tax.

Instead, Rick Santorum continued to be the Rick Santorum of the past dozen or so debates, showing almost none of the fire he is reportedly displaying on the ground in South Carolina and falling back again and again on domestic issues.

Santorum looked rather awkward on stage, rarely gesturing or even changing his tone of voice. Rather than take a strong stance on foreign affairs to counteract the cold-fish feeling, he latched onto issues like abortion and abstinence education.

In those areas, Santorum made a decent showing. But more so than Romney, who simply came off as somewhat rehearsed, Santorum felt stiff, exhibiting almost none of the audience engagement that boosted Perry, parried with Paul and carried Gingrich during last night's debate.

And without Romney's comfortable lead, being stiff at the next South Carolina debate could end up killing Santorum's chances in the Jan. 21 primary.

Notable Quotes:

On poverty in the African-American community: There are three things that work [to get out of poverty]: work, graduate from high school, and get married before you have children.

Record: He [Paul] quotes a lot of left-wing organizations. Well, of course left-wing organizations say a lot of bad things about me. I wear that as a badge of honor.