CHARLESTON, S.C. - The Republican presidential nomination race is momentarily in turmoil. But Mitt Romney, who long ago prepared for a long, methodical slog, is still in strong shape.

"Romney is prepared to grind it out, and no one else is," said Larry Sabato, director of the University of Virginia Center for Politics. "He has a juggernaut, an organization that's first-rate against amateurish organizations in the other campaigns."

Candidates headed Sunday for Florida, site of the next primary, on Jan. 31. They left with a clear message that South Carolina conservatives were uneasy about Romney and want a fighter like Newt Gingrich who articulates their rage toward the political system. They liked Gingrich's combativeness as he promises to "knock out" President Barack Obama and denounces "elites" in Washington, New York and the media.

But Gingrich, the former House speaker who crushed Romney in South Carolina's primary Saturday, is scrambling to assemble a national organization. His campaign has relied almost exclusively on strong TV debate performances. And opponents keep bringing up his controversial political and personal past, which helped sink him in Iowa.

Meanwhile, Rep. Ron Paul and former Sen. Rick Santorum retain sizable followings, and though they've been unable to broaden their support, they still fracture the field. That's common in early nomination contests, and the ultimate winner is usually a candidate like Romney who relies on preparation, organization, and money - not momentum.

Every nonincumbent Republican presidential nominee since 1980 has lost at least one primary on the road to nomination, as unelected incumbent Gerald R. Ford did in 1976. Romney lost South Carolina, but he's placed first or second in the three states that have voted so far. And he's cultivated strong support and organization in Florida for the next challenge.

The Romney camp understood long ago that once the small-state contests are over, the race becomes a quest for delegates to August's Republican National Convention. 1,144 delegates are needed to nominate, and they won't be gathered quickly. Republicans are operating under complex rules this year that award delegates in a variety of ways, making it difficult for anyone to clinch the nomination fast.

By the end of February, only about 15 percent of delegates will have been chosen. Romney's real edge, Sabato said, would become apparent March 6, on which there will be 12 primaries or caucuses. One-fourth of all delegates will be selected that day.

"Only someone like Romney can compete everywhere at once," Sabato said. Gingrich was unable to get on the Virginia's March 6 ballot and reportedly has had trouble filling delegate slates.

Romney has organizations in place in state after state, and "he should be the candidate to be the nominee," said Lance deHaven-Smith, professor of public administration and policy at Florida State University

Romney still faces tall hurdles - the conservative base of his party hasn't rallied to him - but his path ahead should get smoother. He's got a good chance to win Florida, and has strong support in upcoming contests in Nevada Feb. 4, Colorado Feb. 7 and Arizona and Michigan Feb. 28.

Romney, though, still must show he can win somewhere other than New Hampshire, where he owns a home and governed the neighboring state.

Florida is a real possibility. "He's been more evident on television, and Florida Republicans are not as conservative as South Carolina Republicans," said Peter Brown, Orlando-based assistant director of the Quinnipiac University Polling Institute.

Typically, insurgents like Gingrich stumble in big states because the strategy that vaulted them to small-state victory doesn't translate to bigger, more-complex states. Visits to five diners a day with 100 people each, which worked in South Carolina, doesn't have the same impact in Florida, which has more than 19 million people and a half-dozen expensive media markets.

Still, Gingrich will not go away easily. He, Paul and Santorum are tapping into voter frustration with the economy and Washington that's been simmering for years. Romney may have the temperament to bring warring factions together, but voters in South Carolina often saw his style as too sterile.

"Romney is not strong in the areas where Obama is weak," said Kendra Stewart, associate professor of political science at the College of Charleston. "Obama's weaknesses are things like crony capitalism and campaign finances, and Romney has some of those same problems."

Romney also has been hurt by his stiff demeanor.

"He did a great job saving the (2002 Winter) Olympics, but I just can't connect with him," said Bobby Jordan, a Florence, S.C., business owner.

Romney's refusal to release his income tax returns helped fuel that feeling. Not only did it suggest arrogance, but "it makes voters wonder what is it that could come out and make Romney vulnerable against Obama," Stewart said.

Romney plans to release 2010 returns and 2011 tax estimates on Tuesday; he said Sunday that his reluctance to do so earlier was a mistake. Controversy over the issue bogged him down all last week.

Gingrich's confrontational style is very different. He dominated both South Carolina TV debates last week, which were pivotal in persuading voters that he was best able to beat Obama.

"He has a way of seizing the moment like nobody I've ever seen," said David Woodard, professor of political science at Clemson University.

But traditionally, it's hard to convert a candidate's empathy with voter anger into a national campaign against a rival who's assembled a well-financed and nationwide political organization as Romney has.

"Mechanics matter," said Tallahassee-based Republican consultant David Johnson.