David Letterman doesn't respond well to people canceling appearances on his show, so when John McCain suspended his campaign and refused to appear on the show, Letterman ripped him a new one. Then Keith Olbermann comes on to...

Lettermen is his boss after all, and you always want to show loyalty to those who sign the checks, even if they aren't sure who you are. Go play softball with Katie, Senator McCain, but remember DEMOCRACY FIRST! To paraphrase