Mitt Romney romped to a blowout victory in Florida's Republican US presidential primary on Tuesday that put him back in front in the fight for his party's nomination to face President Barack Obama and left chief rival Newt Gingrich reeling but vowing to fight on.

With nearly all returns counted, Romney won 46 percent of the vote to Gingrich's 32 percent in the largest and most diverse of the four states to hold Republican presidential nominating contests so far this year.      Romney, the wealthy former Massachusetts governor and private equity firm executive, bounced back impressively from his decisive loss to Gingrich in the January 21 South Carolina primary.

The victory put Romney back on top in the race for the Republican nomination to face Obama, a Democrat, in the November 6 election. But it came at a cost.

His team spent millions of dollars on mud-slinging TV ads that lampooned Gingrich, raising new doubts about whether Romney can win hearts and minds rather than triumphing by tearing down opponents. Political organizations known as Super PACs, legally independent from the individual candidates, also poured money into advertising in Florida, adding to the negativity of the contest.

The bitter battle in Florida highlighted the deep divisions in a Republican Party struggling to remake its brand.
 Establishment Republicans back Romney and conservative voters favour Gingrich, a dynamic that could complicate the party's effort to derail Obama's re-election bid in November.

The intensely personal attacks also took the focus off of what is expected to be the biggest issue in this election and Obama's most vulnerable flank - the weak economy. Florida, with its 9.9 percent unemployment rate and home foreclosure crisis, was a stark reminder of a nation still reeling from its worst economic crisis since the Great Depression of the 1930s.

But Romney was quick to turn his attack mode back on Obama in a victory speech before jubilant supporters. "Leadership is about taking responsibility, not making excuses," said Romney. "Mr. President, you were elected to lead, you chose to follow, and now it's time for you to get out of the way!"     

He waved away concerns about whether the tough battle between him and his Republican rivals will leave the party divided and easily beatable by Obama. "As this primary unfolds, our opponents in the other party have been watching, and they like to comfort themselves with the thought that a competitive campaign will leave us divided and weak," Romney said.

"But I've got news for them. A competitive primary does not divide us. It prepares us, and we will win," Romney added.  - Reuters