Gingrich's win scaring GOP establishment?

Newt Gingrich's come-from-behind win over Mitt Romney in the Republican presidential primary in South Carolina Saturday made the battle for the GOP nod a brand new race as the focus shifts to Florida, analysts say.

It has apparently shaken up Republican party pundits, too.

"Believe me, Republicans in Congress will be terrified to run with this man for fear that they will lose the House and the Senate," said Fox News senior political analyst Brit Hume. "They will begin to try to do what they can to defeat him."

Also on Fox, conservative commentator Ann Coulter said, "with Newt Gingrich, you throw out the baby and keep the bathwater."

And on "ABC This Week" Sunday, conservative columnist George Will remarked: "All across the country this morning, people are waking up who are running for office as Republicans, from dogcatcher to Senate, and they're saying, 'Good God, Newt Gingrich might be at the top of this ticket."

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The establishment concern is that Gingrich is too polarizing and can't win. But on Sunday, he was confidently predicting victory, saying he is uniquely capable of defeating the president, thanks to his debating skills.

Romney was thrown off in South Carolina, in part, by questions about his taxes and whether he'd release his returns. After insisting he would release them when he filed in April, he now says he'll go public Tuesday with the last return finished - from 2010 - along with an estimate of his 2011 return.

Despite his double digit loss in South Carolina, Romney goes into Florida with an edge. His campaign has been running television ads there for weeks, and his campaign has more money than Gingrich.

But Gingrich has momentum - and South Carolina changed everything, prompting Romney to go on the attack against Gingrich Sunday night.