The former House speaker answered critics who questioned his temperament by saying he would be a nominee who would "shake up Washington." He also accused chief rival Mitt Romney of misstating his dealings with mortgage giant Freddie Mac.
Appearing on ABC's "Good Morning America" hours before a campaign rally in Tampa, Gingrich basked in his come-from-behind triumph in South Carolina. His win made for three different winners in the first three states, with former Sen. Rick Santorum winning Iowa and Romney taking New Hampshire.
Gingrich's campaign said it had raked in $1 million in the first 24 hours since South Carolina's primary Saturday.
Frequently the aggressor in the race, Gingrich is taking fire from all sides now as Florida campaigning ramps up ahead of the pivotal Jan. 31 primary.
Romney has been calling Gingrich a lobbyist and demanded that he release consulting contracts related to Freddie Mac. Gingrich flatly denied lobbying on the firm's behalf.
"It's not true. He knows it's not true. He's deliberately saying things he knows are false," Gingrich said. "I just think that's what the next week will be like.
The battle over financial transparency has gone both ways.
For weeks, Gingrich demanded that Romney release his personal tax records. The businessman and former Massachusetts governor now says he will.
Gingrich told ABC he has campaign lawyers working to make Freddie Mac records public; he said the decision rests with the Center for Health Transformation, which he founded but no longer owns. Two former Gingrich companies earned $1.6 million over eight years from Freddie Mac. Gingrich has said he only earned about $35,000 a year himself.
Gingrich's work for Freddie Mac has come under scrutiny because of its role in the housing meltdown.
On Sunday, some Republican leaders voiced worry about Gingrich's combative style.
He acknowledged Monday that some key players in the party don't want to see him win the nomination, but he also seems to be enjoying the attention.
"I think you're going to see the establishment go crazy in the next week or two," Gingrich said.