Well, my understanding is that McCain was booked on Letterman and cancelled saying that he had to go fix the financial mess. He then shows up being interviewed by Couric (who is also in NYC).
Letterman responds by making all kinds of jokes about McCain, and being po'ed that McCain lied about his reason for not showing.
Seriously, what else would you expect a late night talk show host to do?
I had to wonder what this was all about when Art first posted his rant against Letterman.
http://stupidcelebrities.net/2008/09...-mccain-video/