In the days leading up to the South Carolina primary, former House Speaker Newt Gingrich said he is the best GOP candidate to debate and defeat President Barack Obama, and that wavering conservative voters who might back Rick Santorum or Rick Perry will have "wasted their votes."
On "CBS This Morning" Gingrich told Charlie Rose that to do well against former Massachusetts Gov. Mitt Romney in Saturday's primary, "First, I think I have to prove that I'm a much better debater, much more capable of taking on Barack Obama and standing toe-to-toe with the president and getting across conservative values.
"And second, I have to convince the people who might like to vote for Santorum or might like to vote for Perry that, in fact, those would be wasted votes, and the only way they can get a conservative nominee is to vote for me on Saturday.
"If we can do those two things ... I think we'll win on Saturday. It's going to be a close run, but I think we may be able to pull it off."
Gingrich acknowledged it would be "much harder" on his campaign if Romney wins South Carolina to follow up wins in Iowa and New Hampshire.
"If he's down at 29 or 30 [percent], then I think we're still in a serious race. If he gets up to 40 or 45, then, you know, you have to be realistic about it. I don't see any evidence yet of him doing that well."
Gingrich also said he believed Romney's decision to withhold releasing his income tax returns until later this spring "weakened him a little bit," particularly among voters in South Carolina: "If you're a South Carolinian, you're saying, 'Wait a second: Why don't you want me to know about it? Why are you going to wait until after I have voted?'"
He also dismissed as "pretty silly" charges made by Republicans, including conservative leaders, that the tough primary battle - including volatile attack ads by super PACs - may weaken the eventual nominee, given an advantage to the Democrat Obama.
"Barack Obama is going to have a billion dollars, the power of the White House, and the advantage of most support from the elite media," Gingrich said. "Whoever we nominate had better be able to stand there and win the debate on stage because they're not going to be able to raise the kind of money Obama is going to have. Obama will be plenty tough, no matter who we nominate. That person had better be battle-tested and seasoned and ready. ... We need our best, toughest debate debater to be our nominee."