Newt Gingrich has momentum as South Carolina goes to the polls

Polls show the South Carolina primary Saturday is now Newt Gingrich's to lose after Mitt Romney stumbled this week. But Romney still is favored to win Florida's primary and the nomination.

What a difference a week can make!

When he got up Monday morning, Mitt Romney had a comfortable 23-point Gallup poll advantage over GOP presidential rivals Newt Gingrich and Rick Santorum in national tracking polls.

By the end of the week, and as South Carolinians went to the polls in the first southern primary election, that margin had been cut by more than half to 10 points. Worse yet, some South Carolina polls had Romney dropping behind Gingrich – 26-32 percent in the latest Clemson University Palmetto Poll.

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What happened?

• Rick Perry dropped out and endorsed Gingrich – not only shifting at least some primary votes to the former House speaker but reducing the number of candidates among whom the more conservative vote likely would have been split to Romney’s advantage.

• On Monday and Thursday, Gingrich performed solidly in debates, winning standing ovations while Romney stumbled over questions about his wealth and the amount of income taxes he pays. Gingrich even turned what could have been an “open marriage” blow to his already-questionable marital history into a well-received blast at the “destructive, vicious, negative nature of much of the news media.”

• It turned out that Santorum, not Romney, had won the most votes in the Iowa caucuses. In the overall scheme of things, it wasn’t a big deal. But it was a distraction that helped deflate Romney’s supposed front-runner status.

“Clearly things are collapsing” for Romney, Gallup’s Editor-in-chief Frank Newport told MSNBC.

“The margin for Romney has evaporated this week, and we believe that Gingrich will win the South Carolina primary,” says Clemson University political scientist Dave Woodard. 

That’s the prediction from two other prominent sources.

Nate Silver, who writes the closely-watched FiveThirtyEight blog at the New York Times now gives Gingrich a 64 percent chance of winning South Carolina (compared to just 36 percent chance for Romney). The prediction market Intrade (which can change moment-to-moment) says Gingrich has an 86 percent chance of winning the first southern primary.

"If we get every conservative to decide Newt Gingrich is the right person to stop a Massachusetts moderate, we will win by a surprising margin, and that's going to set the stage for us winning the nomination," Gingrich said as he campaigned Friday.

For their part, Romney and his aides have spent the hours since Thursday night’s debate scrambling to lower expectations.

"I expect that Newt will win some primaries and contests and I expect I will as well," Romney said on the Laura Ingraham radio show Friday. "I'm not expecting to win them all."

But if Romney can recover from this predicted upset (or if he can surprise the pundits and pollsters and win by a slim margin Saturday), he still has a good chance of winning the nomination.

Intrade says he has a 63 percent chance of taking the next big primary – Florida – and a 70 percent chance of being nominated (compared to just 26 percent for Gingrich). Nate Silver gives Romney a whopping 93 percent chance of winning the Sunshine State.

In all of the polls tracked by Real Clear Politics, Romney wins the Republican nomination by an average of 11 percentage points. In all of the general election surveys pitting each of the GOP candidates against Barack Obama, Romney comes much closer than Gingrich, Santorum, or Ron Paul to defeating the incumbent president – the clearest gauge of his electability.

“I think anything is possible,” says Gallup’s Frank Newport. “It wouldn’t be out of the realm of possibility if Romney recovers. We’ll wait and see.”

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