Updated: 11:24 p.m. ET
Mitt Romney has defeated Newt Gingrich decisively in the Florida Republican primary in a victory that reestablishes the former Massachusetts governor as the clear frontrunner for the Republican presidential nomination.
"I stand ready to lead this party and to lead our nation," Romney told cheering supporters in Tampa after his victory became clear.
Gingrich, meanwhile, vowed to fight on in the wake of a potentially-devastating loss, telling supporters, "we are going to contest every place and we are going to win, and we will be in Tampa as the nominee in August."
Gingrich notably did not congratulate Romney in his remarks, the tone of which was perhaps best captured in how they concluded: "I promise you that if I become your president, I pledge to you my life, my fortune and my sacred honor. This is about America. Thank you."
With 99 percent of precincts reporting, Romney had 46 percent of the vote, followed by 32 percent for Gingrich, 13 percent for Rick Santorum and 7 percent for Ron Paul.
Neither Santorum nor Paul seriously competed in the Sunshine State, a winner-take-all contest whose 50 delegates will go entirely to Romney.
Romney's victory in Florida comes ten days after Gingrich's double-digit win in the South Carolina primary, a result that seemed to rejuvenate the former House speaker's campaign. In the wake of that outcome, Romney pivoted to a far more aggressive posture, harshly criticizing Gingrich on the stump, the debate stage and in a barrage of negative advertising.
Romney acknowledged the nastiness of the Florida fight in his remarks Tuesday night, telling supporters, "primary contests are not easy, and they're not supposed to be."
"A competitive primary does not divide us, it prepares us, and we will win," added Romney, who spent the majority of his remarks attacking President Obama as a failed leader seeking to "fundamentally transform America."
Vowing that a Romney presidency would "begin a new era of American prosperity," he told the president, "it's time for you to get out of the way."
The victory, in the nation's fourth-largest state, comes in a state Romney lost to John McCain in the 2008 GOP primary -- a loss that effectively ended his bid for the presidential nomination four years ago.
Romney performed well throughout the state, amassing particularly solid gains in South Florida and Miami as well as the central part of the state. Bolstered by strong organization in recent weeks, Romney also did very well with Florida's sizable number of early and absentee voters.
Exit polls showed Romney dominating Gingrich among women - 52 percent to 28 percent - and also besting him among men, 41 percent to 36 percent. Romney was seen as the more electable candidate by 53 percent of Florida GOP voters (compared to 29 percent for Gingrich) and won more than half of Hispanic GOP primary voters - 14 percent of the electorate.
In an outcome likely to infuriate Gingrich, who has relentlessly cast Romney as insufficiently conservative, self-identified conservatives (seven in ten primary voters) favored Romney over Gingrich 41 percent to 37 percent, according to exit polls. Tea Partiers and white evangelicals were essentially split between the two candidates.
Romney's debate performances in Florida, in which he often had his rivals on his heels, were widely praised - a reversal from the South Carolina debates, where it was Gingrich who shined. In exit polls in both states, roughly two in three voters said the debates were an important factor in their decision. Exit polls in Florida showed late deciders favoring Romney 45 percent to 34 percent for Gingrich.
Romney and the super PAC backing him also appear to have widely outspent Gingrich (and his super PAC) in advertising, with media buying firms saying that Romney and his super PAC spent roughly $16 million to a relatively paltry $4 million or so for Gingrich and his super PAC. (The Romney campaign disputes this, claiming the disparity was closer to 2-1.)
Among the 41 percent of voters who said in exit polls that campaign ads were an important factor in their vote, Romney bested Gingrich 59 percent to 25 percent.
As Romney assailed Gingrich in ads and on the stump for his past record - including his links to Freddie Mac and his ethics reprimand in the House - Gingrich's rhetoric against his rival grew increasingly heated. Gingrich took to casting Romney as a liberal on abortion (and other issues) whose dishonesty proves he cannot be trusted.
Despite the heavy focus on the early nominating contests, the race for delegates is far from over. Iowa, New Hampshire, South Carolina and Florida have awarded just 112 delegates total - and 1,144 are needed to secure the nomination.
After a feverish January, the nominating contest slows down somewhat in February ahead of "Super Tuesday" on March 6. Caucuses will be held in Nevada on February 4; in Colorado and Minnesota on February 7; and in Maine ending on February 11. Arizona and Michigan also hold primaries on February 28.
Romney won Nevada, Michigan, Maine, Colorado and Minnesota in his 2008 presidential run, and he has superior organization, financial resources and establishment support to Gingrich. (On Tuesday night, Romney announced he raised more than $24 million in the fourth quarter of 2011, to Gingrich's less than $10 million.) But the former House speaker is vowing not to leave the race anytime soon, predicting before the Florida vote that the contest would go for another six months - "unless Romney drops out earlier."
In addition to assailing the president for "managing the decay" of America and other perceived failures, Gingrich said he would overcome Romney's financial advantage, telling supporters "people power [will] defeat money power in the next six months." Behind him supporters held signs that read "46 states to go," a message he said his campaign wanted to send so the "elite media" that had left him for dead twice before understood he wouldn't leave the race.
After celebrating his Florida win in Tampa, Romney was scheduled to travel to Minnesota for a campaign stop before moving on to Las Vegas. Gingrich was scheduled to travel straight to Nevada; Santorum was watching the Florida returns from that state, and planned to campaign in Colorado Wednesday before returning to Nevada. Paul, who is focused on accruing delegates as opposed to winning the momentum battle, was scheduled to attend a series of events in Las Vegas.
Speaking in Henderson, Nevada Tuesday night, Paul told supporters that he had called to congratulate Romney and tell him "I would see him in the caucus states."
"You know, a few months ago, there were - how many candidates were there?" he added. "There were nine. But tonight we're down to four...I saw a statistic that we're in third place when it comes to delegates. That's what really counts. And we've only gotten started!"
Santorum, meanwhile, told CNN that "Newt Gingrich had his shot and couldn't hold it, and couldn't deliver in Florida."
The former Pennsylvania governor, who is hoping to take the mantle as the consensus conservative alternative to Romney from Gingrich, said in remarks to supporters soon after that Gingrich "had his opportunity" but "it didn't work," adding, "he became the issue."
Despite having made some harsh attacks over the past ten days, Santorum also criticized his rivals for the nasty fight in Florida, breaking with Romney's argument that it will strengthen the eventual nominee.
"What we saw in the last few weeks in Florida," he said, "is not going to help us win this election."