(CNN) -- Having let his rivals battle it out in the early states, Rudy Giuliani faces a must-win situation in Florida when the state's Republicans head to the polls next week.
In what many political strategists called a risky strategy, the former New York mayor essentially sat out the early contests in Iowa, New Hampshire, Michigan, Nevada and South Carolina and focused on Florida and its January 29 primary.
And as his rivals notched victories, Giuliani has mostly been out of the headlines, and his standings in the national polls slipped. He is banking on a win in Florida, with its 57 delegates, to propel him back into the thick of the race and restore his front-runner status.
In the last month, Giuliani has seen three men pass him by in national polls, and they are working hard to upset Giuliani's Florida strategy. Sen. John McCain comes to Florida with momentum from his wins in South Carolina on Saturday and in New Hampshire earlier this month. Mitt Romney won in Nevada on Saturday as well as in Michigan and Wyoming, and Mike Huckabee won the Iowa caucuses. Watch how the GOP race in Florida is heating up »
Former Republican Sen. Fred Thompson is also continuing his presidential run, but his disappointing third in South Carolina may have fatally wounded his campaign.
A turnaround is critical if Giuliani is to do well one week later on Super Tuesday, February 5, when Republican voters will pick their favorites in over 20 states, including mega-states like California, New York, Illinois and New Jersey. Watch how Giuliani counts on Florida »
"What happened is it has became a very competitive race. ... Four or five people -- four, five -- have a chance at getting the nomination," Giuliani told supporters in Daytona Beach, Florida, on Monday. "And Florida will give a lot of definition to that."
The GOP race has also changed since Giuliani was the front-runner, as concerns about the economy top the worries of Republican voters.
"I think the economy will be the major issue. Florida has the struggling economy now, and we have a population that is somewhat cost-sensitive," said professor Lance DeHaven-Smith of Florida State University.
While Giuliani was talking up his national security credentials on the campaign trail in the early portion of his campaign, he has since turned his attention toward the economy.
"The very best things we could do is a major stimulus package that would lower taxes, and lower taxes dramatically," Giuliani said in Orlando, Florida, on Monday. "And that's why I proposed the largest tax reduction in American history."
In an attempt to partially blunt his rivals' momentum, Giuliani has begun to question their economic records and to highlight his record of cutting taxes in New York City. In particular, Giuliani is focusing his fire on McCain, who may be his biggest threat in Florida.
"I supported the Bush tax cuts," Giuliani said. "John McCain sided with the Democrats and voted against the tax cuts. Mitt Romney was equivocal in his support for the Bush tax cuts."
But McCain is ready to press the advantage he earned from his victory in South Carolina, saying Monday, "We come into Florida with some wind at our back."
On Monday, McCain showed he was ready to battle Giuliani on economic issues, saying, "I understand the economic difficulties facing Florida and this country." He also said he opposed the Bush tax cuts because it did not include accompanying spending cuts.
McCain, too, said he was ready for an economic stimulus package but warned he would oppose it if it contains unnecessary spending.
"If Congress loads it up with pork barrel projects, which is the major reason we have gotten into the mess, then obviously I would be in opposition to it," McCain said in Miami on Monday.
Romney also focused on his economic message and touted his experience as a businessman Monday.
"I spent my life in the private sector and spent my time helping to create jobs," Romney told supporters during an appearance in Orlando, Florida.
It was Romney's economic message which helped him to win in Michigan with its struggling auto industry,
Florida has a large population of seniors, many on fixed incomes, and they are worried about taxes and inflation. Heeding those concerns, Romney is tailoring his message to them.
"Anybody in the who 65 years of age and older, they'd have no payroll tax, either by their employer or by themselves," Romney said while explaining his economic proposal. Romney is also proposing tax rebates for people in the lowest tax bracket and incentives for corporations.
Florida is a regionally- and ideologically-diverse state, and the contest will mark the first time in the GOP primary fight that all of the top-tier Republican candidates will be competing in the same contest.
Each of the candidates has a natural constituency in the state. In the rock-solid, conservative northern portion of the state that borders Georgia and Alabama, Huckabee, a former Arkansas governor and Baptist preacher, will bring his message mixing cultural conservatism and economic populism that propelled him to victory in Iowa.
The other hand, Romney, who won his native state of Michigan, may target the southwest portion of Florida around Fort Myers and the Sarasota area, which is home to many transplanted people from the Midwest.
McCain, a former POW during the Vietnam war, has done well in areas with military installations, is expected to target Tampa, which is home to U.S. Central Command, the large naval installation in Jacksonville, and military retirees across the state.
Giuliani, meanwhile, is expected to focus on the areas around Palm Beach, Broward County, and Miami, which is home to many transplanted New Yorkers and retirees originally from the northeast. E-mail to a friend
CNN's John King and Mary Snow contributed to this report.