Two new polls suggested Mitt Romney had moved out in front of Newt Gingrich in the so-called Palmetto State, where Republican voters are far more socially conservative than those in New Hampshire and hold the South's first primary in two weeks.
The former Massachusetts governor was poised to coast to victory in Tuesday's New Hampshire primary, but victory was less certain in South Carolina. Not only are social conservatives wary of Romney's record, but the evangelicals among them deeply distrusted his Mormon faith when he ran for president in 2008.
Just a few days ago, Gingrich was well ahead of Romney in South Carolina. No longer, suggests a Rasmussen Reports poll that had Romney at 27 per cent among the state's primary voters, followed by a surging Rick Santorum with 24 per cent and Gingrich at 18 per cent.
An American Research Group poll in the state, meantime, put Romney at 31 per cent, and Gingrich and Santorum at 24 per cent each. Since 1980, the winning candidate in South Carolina has gone on to win the party's nomination.
"It's going to come down, as it always does, to South Carolina," Sen. John McCain, who won the state in 2008 during his own run for the nomination, said Friday as he campaigned with Romney in Conway, S.C.
"If Mitt Romney wins here, he will be the next president of the United States."
The new polls reflect a stunning ascent for Santorum, the former Pennsylvania senator who's a staunch social conservative opposed to same-sex marriage, abortion and even birth control. He had a mere one per cent of support in South Carolina just two months ago.
And they're particularly grim for Gingrich, described by one pundit as the "Pillsbury Doughboy on a rampage."
Gingrich, indeed, has been in a prolonged snit following his distant fourth-place finish in the Iowa caucuses earlier this week.
The former speaker of the House of Representatives blames Romney for his poor showing, accusing him of financing a series of negative ads against him in the state. Gingrich has vowed revenge, and a pair of pre-primary debates in New Hampshire this weekend promise to get testy.
One of Romney's rivals "will eventually emerge as the conservative alternative and will beat Romney," he predicted in an interview with ABC News on Friday.
Even if Romney managed to win the nomination, his performance against Obama in presidential debates would be laughable, Gingrich added.
Gingrich may be injecting vim and vigour into the Republican race, but he's making a fool of himself in the process, said Cal Jillson, a political science professor at Southern Methodist University in Dallas.
"The problem is, he has this image of being the Pillsbury Doughboy on a rampage and that's not very threatening, nor is it very attractive," Jillson said.
Gingrich's latest blasts against Romney came a day after his campaign unveiled an attack ad of its own in New Hampshire and South Carolina, assailing Romney's proposals to jump-start the U.S. economy.
"Romney's economic plan? Timid," the ad reads. "Parts of it virtually identical to Obama's failed policy. Timid won't create jobs and timid certainly won't defeat Barack Obama."
The ad's timing was off, however, thanks to Friday's big economic news. New Department of Labor figures show 200,000 jobs were created in the month of December as the country's unemployment rate fell below nine per cent.
"We're making progress," Obama said of the numbers.
"We're moving in the right direction. And one of the reasons for this is the tax cut for working Americans that we put in place last year."
Romney's campaign, however, returned the Obama insults. Restore Our Future, the so-called super-committee behind Iowa's anti-Gingrich ads, announced Friday it had purchased full-page newspaper ads in in New Hampshire and South Carolina that liken Gingrich to Obama.
"On issue after issue, Newt Gingrich and Barack Obama have so much in common; the right choice is to choose neither," the ad said, pointing to Gingrich's support of a federal bank bailout and amnesty for illegal immigrants.
Romney's on solid ground right now but a lot can transpire in two weeks in a race that has been nothing if not wildly unpredictable, Jillson pointed out.
"Romney stands a chance to close this thing up in South Carolina and then Florida," he said.
"If he sweeps Iowa and New Hampshire and goes into the south and wins twice there, I don't think anyone else has the fundraising to stay in the race. Nonetheless, South Carolina is still in play. There's not enough time for much to change in New Hamsphire, but there's lots of time for anti-Romney attacks and strategies to be put in place in South Carolina."
McCain and other high-profile Romney supporters did their bit to solidify their man's lead on the campaign trail on Friday, taking aim at both Gingrich and Santorum. Both candidates supported earmarks in Congress, McCain said, adding: "My friends, earmarks are the gateway to corruption."
"Earmarks" refer to federal funds that congressional lawmakers direct to specific projects back in their home states. It's become a dirty word in the United States, a symbol of the sort of pork-barrel politics some are willing to resort to in order to get re-elected.
Santorum, for his part, branded Romney a flip-flopper.
"The only way Republicans lose is if we screw this up and nominate another moderate who has taken multiple positions on every major issue of our time," he said in a fundraising appeal.
Former Utah governor Jon Huntsman, meantime, was basking in the glow of his endorsement from the Boston Globe, the biggest newspaper in Massachusetts. It's the second time the paper has snubbed Romney, who ably governed the state for four years.
Huntsman, who bypassed Iowa to focus on New Hampshire, predicted the state's voters would cast their ballots for a realist on Tuesday.
"If you don't light your hair on fire, you don't sign those silly pledges, you don't have all those 'oops' moments, you're not going to get as much airtime, and people won't talk about you as much," he said at a campaign stop in New Hampshire.
"(Voters) will enjoy watching the circus play out and all of the political theatre until they have to stare down the ballot box."