CBS

TAMPA, Fla. (AP) -- Mitt Romney won a commanding victory in the Florida primary Tuesday night, rebounding from defeat a week earlier and taking a major step toward the Republican presidential nomination. Despite the one-sided result, Newt Gingrich vowed to press on.

"Thank you FL!" an exuberant Romney tweeted minutes after the race was called. "While we celebrate this victory, we must not forget what this election is really about: defeating Barack Obama."

Returns from slightly more than half of Florida's precincts showed Romney with 47 percent of the vote, to 33 percent for Gingrich.

Former Pennsylvania Sen. Rick Santorum had 13 percent, and Texas Rep. Ron Paul 7 percent. Neither mounted a substantial effort in the state.

The winner-take-all primary was worth 50 Republican National Convention delegates, by far the most of any primary state so far.

But the bigger prize was precious political momentum in the race to pick an opponent for Democratic President Barack Obama this fall

That belonged to Romney when he captured the New Hampshire primary three weeks ago, then swung stunningly to Gingrich when he countered with a South Carolina upset 11 days later.

Now it was back with the former Massachusetts governor, after a 10-day comeback that marked a change to more aggressive tactics, coupled with an efficient use of an overwhelming financial advantage.