Emboldened by his victory in South Carolina's Republican primary, Newt Gingrich said Sunday his hardline conservative views and confrontational style will be needed by Republicans this fall to fight President Barack Obama's "billion-dollar war chest" and take back the White House.

In several televised interviews, the former House speaker said rival Mitt Romney was a moderate who left GOP voters cold and that only he, Gingrich, could go "toe to toe" with Obama.

"I think in South Carolina it began to become really clear that if you want to beat Barack Obama, then Newt Gingrich is the only person who has the background, the experience and the ability to get on the stage and drive home a conservative message with authenticity," he said.

Gingrich's win in South Carolina has helped invigorate his once struggling campaign and cast fresh doubt on Romney's ability to easily cinch the Republican nomination.

Returns from 95 percent of the state's precincts showed Gingrich with 41 percent of the vote to 27 percent for Romney. Former Pennsylvania Sen. Rick Santorum was winning 17 percent, and Texas Rep. Ron Paul 13 percent.

Next stop is Florida, where Gingrich and Romney will compete with Santorum in the Jan. 31 primary. Paul has said he was bypassing the state in favor of smaller subsequent caucuses.

Romney and his supporters are dismissing Gingrich's win in South Carolina and say his nomination would be a disaster for the Republican Party, citing his rocky tenure leading House Republicans in the 1990s and allegations of ethics violations.

"I think Newt Gingrich has embarrassed the party, over time," said New Jersey Gov. Chris Christie. "Whether he will do it again in the future, I don't know. But Gov. Romney never has."

Christie, who has endorsed Romney's nomination, said he would "listen" if Romney were to ask him to be his running mate this fall. But, he added, he expects to remain in his current position as governor.

Gingrich says his views on lower taxes, less government regulation and foreign policy put him in stark contrast to Obama and that the dynamics of a Gingrich-Obama fight are much more alluring to voters.

"I think Gov. Romney's core problem was that he governs (as) a Massachusetts moderate, which by the standards of Republican primary voters is a liberal. And he can't relax and be candid," he said.

Gingrich spoke on CNN's "State of the Union," NBC's "Meet the Press" and CBS "Face the Nation." Christie spoke on NBC's "Meet the Press."