Jim Rutenberg

CHARLESTON, S.C.: Surprising his rivals and upending the Republican race for the presidency, Newt Gingrich won the pivotal South Carolina primary on Saturday, 10 days after a fourth-place finish in New Hampshire left the impression his candidacy was all but dead.

Gingrich rode to victory by winning a plurality among a wide range of important Republican voting blocs, outperforming the rest of the four-person field among evangelical Christians and tea party supporters, men and even women, despite the publicity given to problems in his first two marriages.

Gingrich leaves for Florida today in the best position to pose a singular insurgent threat to Mitt Romney, the favored candidate of the Republican establishment, in the weeks, if not months, to come.

Romney, who left New Hampshire as the presumed front-runner, is now one of three Republicans to have won one of the first three nominating contests, having been stripped of his incorrectly declared victory in the Iowa caucuses last week, a win that was instead given to Rick Santorum, who placed third Saturday.

“This race is getting to be even more interesting,” Romney told his supporters in Columbia after his second-place finish Saturday. “This is a hard fight because there is so much worth fighting for. We’ve still got a long way to go and a lot of work to do.”

But Romney still has a considerable advantage over Gingrich when it comes to money and organization, both of which will be vital in the expensive campaign state of Florida, which has its primary a week from Tuesday.

And Florida is different political terrain from South Carolina, where Gingrich had cultivated the tea party movement’s leaders since its inception.

Gingrich seized on his South Carolina victory less than an hour after the polls closed.

“Thank you, South Carolina! Help me deliver the knockout punch in Florida. Join our Moneybomb and donate now,” he wrote on his Twitter feed. His campaign placed a large advertisement on the Drudge Report website, popular among conservatives, seeking donations as well.

The “super PAC” supporting Gingrich, Winning Our Future, indicated it was ready to run advertisements arguing, among other things, that President Barack Obama would be able to eviscerate Romney in debates by holding his more liberal past positions against him.

Revival of campaign

For Gingrich, the victory marked a decisive revival for a candidacy that had been declared dead at least twice, and that came back to life in the last days before the primary in South Carolina partly because of his commanding debate performances, which his aides are using as a selling point in their argument that he provides the best challenge to Obama.

The victory for the former House speaker effectively resets the Republican nominating contest for the next important test in Florida, which Romney’s campaign considers an important bulwark for his candidacy.

It is one of the most expensive states to campaign in, and Romney’s aides have been counting on being able to outspend and outperform Gingrich there.

But as Gingrich began to climb rapidly in polls this week, and Romney’s aides prepared for defeat, they said they would not be so bold as to predict an easy time in Florida, given how the momentum could affect the dynamic of the next contest.

If nothing else, the fact that just over half of South Carolina voters said in exit polls that they made up their minds at the last minute shows just how fluid and restive the Republican electorate remains — a troubling sign for Romney that Gingrich is poised to capitalize upon.

And after being so confident just 10 days ago — before its declared victory in Iowa was rescinded and Gingrich began his rise — the Romney campaign is now fighting not only the perception that Romney cannot consolidate broad support among conservative voters, but also at least one troubling fact of history: No Republican has gone on to win the party’s nomination without winning South Carolina since before 1980.

Even Gingrich’s rivals acknowledge that it was once again his performances at pivotal debates that most positively affected his showing in South Carolina — notably at a Fox News debate on Monday in Myrtle Beach.

It was there that he lambasted the Fox moderator Juan Williams for asking whether some of Gingrich’s statements, like calling Obama a “food-stamp president” and suggesting that poor children work as janitors to learn a work ethic, were not insensitive to black people.

His well-received debate performances appeared to come at just the right time: Exit polls showed that more than half of the primary’s voters had made up their minds within the last few days.

And for nearly two-thirds of primary voters, the recent debates were important factors in their decision. About one in 10 said it was the most important factor.