TAMPA, Fla. -- Florida defied the Republican establishment in pushing its way to the front of the presidential primary calendar.

It's a state whose GOP establishment has been shaken up in recent elections. Now it's providing a test of whether the party's establishment candidate can rebound from a stinging loss in South Carolina to recapture the momentum in this consistently unpredictable nomination battle.

Former House Speaker Newt Gingrich roared out of South Carolina with a landslide upset that dramatically changed perceptions of a race in which former Massachusetts Gov. Mitt Romney hadn't necessarily had the love of his party's conservatives but did have a consistent argument that he would be the most "electable" of the party's contenders. But exit polls in South Carolina found that in his sweep of most demographic and ideological groups, Mr. Gingrich also won voters who considered defeating President Barack Obama the most important issue in the race.

Mr. Gingrich's showing was rooted in two strong debate performances, in Myrtle Beach and in Charleston, where he memorably clashed with moderator John King on the "open marriage" allegations of his second wife. And, among many voters, it was reinforced by an embrace of Mr. Gingrich's quite different definition of "electability."

Mr. Romney has pointed to his relative strength among independent voters and his ability to win a race for governor in a Democratic state as evidence of his ability to prevail in a general election. Mr. Gingrich sustained his candidacy through times when many thought it doomed with a series of strong debate performances. A constant element of his stump speech is a vow to challenge Mr. Obama to a series of "seven Lincoln-Douglas style debates."