TAMPA, Fla. — After three bruising contests that each produced different winners, the Republican nominating contest has moved to a state that is much more like the rest of America in its diversity, its multiplicity of media markets and its voter base, which is less likely to be swayed by the family values issues that played a dominant role in prior contests in Iowa and South Carolina.
Florida is in many ways composed of distinctly different parts, posing particular challenges to the candidates as they try to appeal to the immigrant-rich Miami region, the more conservative north or the retirees sprinkled around the state who carry with them the political loyalties bred elsewhere.
But one thing that unifies the Republican primary voters who will cast ballots on Jan. 31, analysts said, is that they are less ideological and want Florida to be the tie-breaker state, choosing the candidate who is best able to defeat President Obama.
Jobs and the still-depressed housing market are top concerns of voters, polls show. The state, which has a 9.9 percent unemployment rate, and where one in every 360 housing units is in foreclosure, lags behind the rest of the country in rebounding from the recession.
“We’ll see who can do the better job in November, not just who’s the most conservative,” said Fernando Perez, 36, a medical equipment salesman, who listened to Mitt Romney speak at a rally in Ormond Beach, Fla., on Sunday evening. “The economy is definitely No. 1 for me.”
The Florida race is the first contest that approaches the scale of a general election fight, where retail campaigning is significantly overshadowed by advertising.
In many ways, the primary battle here will be a showdown between the substantial advantages Mr. Romney has built through his fund-raising and on-the-ground organization — including a successful early-voting operation that locked in many of his supporters before his loss in South Carolina — and the momentum and grass-roots energy that Newt Gingrich picked up over the last week.
Mr. Romney holds significant advantages in money and organization: he has already spent at least $4 million on advertising here, according to an independent analysis. “It’s a very, very different race going to Florida now,” said Stuart Stevens, a strategist for Mr. Romney.
Aides believe Mr. Romney has at least 125,000 votes already in the bank through absentee ballots and early voting, which people can do more than a week before the election. Most of those absentee ballots votes were cast when the former Massachusetts governor had an aura of inevitability after winning the New Hampshire primary, and before Mr. Gingrich’s runaway victory in South Carolina on Saturday.
But Mr. Romney’s big edge in money and organization may play a smaller role here than expected. Floridians have been exposed to saturation coverage of the nominating fight since last year, muffling the impact of attack ads, and there are two more debates, one on Monday night and another on Thursday.
Mr. Gingrich performed well in South Carolina partly because many voters believed that his debate performances suggested that he could prove a formidable opponent to Mr. Obama, something that could play out here as Republicans seek a viable candidate for November.
“The first couple of polls out after tomorrow night’s debate that look at how Obama stacks up against Romney and Gingrich will have a big impact” on whom voters rally behind, said Susan MacManus, a political scientist at the University of South Florida, where the debate takes place.
An intriguing wild card may be the former Florida governor Jeb Bush, whom many establishment Republicans once hoped would enter the race. After Mr. Gingrich and Mr. Romney sought his endorsement, he decided to stay neutral, he told Bloomberg News over the weekend.
But Mr. Bush called on Mr. Romney to release his tax returns, and on Sunday Mr. Romney — under pressure from other Republican leaders — said he would do so, on Tuesday. Mr. Bush also urged the candidates to tone down their harsh rhetoric on issues like illegal immigration, to appeal to independent voters in the general election, a tactic they have mostly ignored until now in the quest to rally the conservative base.
Florida’s Republican governor, Rick Scott, who was elected in 2010 by a razor-thin margin with Tea Party support, has also said he is inclined not to endorse a candidate, although he was approached by three of the four.
The Florida primary is closed, so only Republicans can participate, unlike the first three contests, which allowed independents or Democrats to cross over and vote. Florida Republicans are hardly monolithic, with Cuban-Americans in the south to rock-ribbed social conservatives in the panhandle, mixed with a large influx of new voters and retirees. Party officials estimate that two million people will cast ballots on Jan. 31.
Fifty delegates are up for grabs in Florida, all of which will be awarded to the winner of the primary, making the battle critical for Mr. Romney and Mr. Gingrich in their effort to win 1,144 delegates needed to clinch the nomination.
Going into Florida, Mr. Gingrich also enjoys momentum coming out of South Carolina. And Tea Party sentiment, which helped fuel Mr. Gingrich’s rise in South Carolina, is alive and well in Florida and was important in the races for governor and Senate in 2010.
The Gingrich campaign is not as skeletal here as it was a few weeks ago. Mr. Gingrich took a detour from campaigning in South Carolina to open an office in Orlando, and he has announced a chairman and a deputy for each county.
Besides perennial issues that matter to Florida Republicans like the economy, immigration and the size of the federal government, Mr. Gingrich’s rivals are likely to go after him here over his temperament.
Justin Sayfie, a co-chairman of the Romney campaign in Florida, conceded that Mr. Gingrich would arrive in the state on Monday with a wave of momentum. But the organization Mr. Romney has been building for months, he said, cannot be overlooked.
“There are nine long days until the Florida primary date,” Mr. Sayfie said. “As we saw in South Carolina, that’s enough time for momentum to shift considerably. By Tuesday night, South Carolina’s results will seem a distant memory and the candidates will be sized up in the final week on how they are faring with Florida’s diverse and titanic G.O.P. electorate.”
Rick Santorum, who will have a harder time in the state with its smaller evangelical Christian bloc, campaigned in Florida on Sunday, but since the state has a winner-take-all contest, his campaign may not devote as many resources here as it did to the other states.
The fourth candidate still in the race, Ron Paul, does not plan to actively campaign in the state, instead looking ahead to several Western states with caucuses.