John McCain announced today that he would suspend his presidential campaign until the current economic crisis is settled, leaving some big holes in this week's TV schedule — most especially, this Friday's suddenly in-jeopardy presidential debate, which McCain is seeking to postpone (Barack Obama and debate organizers have rejected the idea). In the short-term, however, McCain pulled out of his planned appearance tonight on Late Show with David Letterman, and the host is pissed. Seems McCain told Letterman that he was canceling so that he could rush back to Washington D.C., but then Dave caught wind that McCain hadn't gone anywhere — that, in fact, he was just down the street taping an interview with CBS anchorwoman Katie Couric. What followed was an on-screen excoriation, according to the Drudge Report:

Dave even cut over to the live video of the interview, and said, "Hey Senator, can I give you a ride home?" Earlier in the show, Dave kept saying, "You don't suspend your campaign. This doesn't smell right. This isn't the way a tested hero behaves." And he joked: "I think someone's putting something in his metamucil." "He can't run the campaign because the economy is cratering? Fine, put in your second string quarterback, Sarah Palin. Where is she?" "What are you going to do if you're elected and things get tough? Suspend being president? We've got a guy like that now!"

Senator McCain, you can tweak Barack Obama all you want, but nobody messes with Dave. A man exempt from "527 group" special interest laws, the Late Show host has a big microphone, and he's not afraid to flick a candidate into the background skyline like a note card gone wrong.