Romney and Letterman discissing Sarah Palin

“Now what about that Sarah Palin," says Letterman, who had to apologize for an off-color joke about the former Alaskan governor's daughter last year. "She’s not ready to be president, is she?”

She’s terrific,” Romney rapidly replies to derisive audience laughter. “She really is! She’s terrific. She’s got energy, passion – by the way, you know, be careful what you say about her.”

Letterman says he knows.

Romney adds with a smile, “She has a rifle, you know.”

That's funny.