Former House Speaker Newt Gingrich says he thinks his performance in debate against fellow Republicans shows he's best qualified to take on President Barack Obama in the fall.

Gingrich tells "CBS This Morning" the party will need a first-rate debater against Obama because he has ample money and the trappings of the presidency.

The Georgia Republican concedes it will be harder to head off Mitt Romney if he gets over 40 percent of the vote in South Carolina's primary Saturday. But he says Republicans "need somebody who is a solid conservative who can stand toe to toe with Obama and defeat him in the debates."

Gingrich says votes for Rick Perry or Rick Santorum "would be wasted" because neither has a chance to block Romney's path to the nomination.