Mitt Romney is looking to clench his second win of the primary season tonight in Florida, a battleground state that will be a crucial test for candidates in the November election.
Preliminary exit polls found that Republican voters were heavily influenced by the debates and campaign ads that dominated the Florida airwaves for weeks. As in Iowa and South Carolina, voters were looking for the candidate who has the best chance to defeat President Obama. About two-thirds of Florida voters in these preliminary results said they would be satisfied with Romney as the Republican nominee.
The former Massachusetts governor and super PACs that support him spent millions attacking his chief rival, Newt Gingrich, and Romney assailed the former House speaker at Thursday's debate sponsored by CNN, the Florida Republican Party and the Hispanic Leadership Network.
Romney's strategy apparently resonated with voters, as he quickly jumped in polls while Gingrich fell.
"With a turnout like this, I'm beginning to feel we might win tomorrow," Romney, who kept his schedule light today, said at a campaign stop on Monday, a sign that the campaign is confident of a win.
Romney jumped into Florida well before any of his competitors, launching TV ads even before the South Carolina primary. That move could bode well for him, as exit polls showed that four in 10 voters made up their mind before the start of the month, much more than in South Carolina.
Only four candidates on the ballot today are still in the race, but the Florida primary is really more of competition between Romney and Gingrich.
Both candidates and the super PACs supporting them have spent millions of dollars in attack ads, but the former House speaker is far outweighed by his chief rival when it comes to spending.
Romney's campaign spent nearly $7 million on television ads leading up to the primary, more than six times that of Gingrich, whose campaign spent about $1 million.
The super PACs have even outspent the campaigns. The group supporting Romney, Restore Our Future, spent a whopping $8.5 million on ads in Florida, while Winning Our Future, the super PAC backing Gingrich, spent about $2.2 million.
Neither Rick Santorum nor Ron Paul, the other two candidates in the race, are on the airwaves. Both are focusing on Nevada, the next voting state.
Romney was actually on the airwaves more in 2008, when he lost the state to Sen. John McCain. But in this race, he has dominated the airwaves against his rivals, airing almost 13,000 ads on broadcast television across the state, as of Wednesday, Jan. 25 -- much more than Gingrich and his support groups, which together have aired about 200 spots, according to the Weslayan Media Project.
Ninety-two percent of all TV ads aired in the Sunshine State over the last week were negative, mostly targeted at Gingrich, according to Kantar Media Campaign Media Analysis Group.
But despite the ads against him and his slump in the polls, Gingrich has given no signs of letting up, staying firm that he will stay in the race for the foreseeable future.
"I'm not going to lose big here," the former House speaker told ABC News today, adding that it's "six months or eight months" away from being over.
"I would say June or July," he added, "unless Romney drops out earlier."
Gingrich had made his mark by stellar debate performances that set him apart from other candidates. It was one of the reasons why he won by an overwhelming margin in South Carolina. But that changed last week as Romney aggressively attacked Gingrich on his past connections to Freddie Mac and his immigration ads.
Gingrich attempted to turn the tables on his rival in subsequent ads attacking his record as Massachusetts governor. In a new robo-call released ahead of the primary, Gingrich charged Romney with taking away money for kosher food for Holocaust survivors in a senior center.
Fifty delegates are at stake in today's primary, an important number for Romney.
"Today, Florida is the most important thing in the world to me," he told ABC News today.
Romney led by double digits over Gingrich in most polls. The most recent poll, conducted by Quinnipiac University, found Romney outshining Gingrich 43 percent to 29 percent, followed by Santorum and Paul tied at 11 percent.
Santorum, whose daughter was hospitalized earlier this week, was absent from Florida, focusing instead of campaigning in Colorado and Nevada, where caucuses will be held Saturday.
Paul plans a Florida election night party today -- but in Nevada.
ABC News' Elizabeth Hartfield contributed to this report.