On Liddy:
Letterman questioned him about Palin's claim that Democratic presidential candidate Barack Obama "palled around with terrorists," and McCain backed her up, saying his opponent need to better explain his relationship with former Weather Underground activist William Ayers.
"Did you not have a relationship with Gordon Liddy?" Letterman asked about Watergate burglar G. Gordon Liddy.
McCain said he knew him. Then, after a commercial break, McCain said, "I know Gordon Liddy. He paid his debt, he went to prison ... I'm not in any was embarrassed to know Gordon Liddy."
