I write topical comedy for a living myself (for radio syndication), and I can watch his monologues and tell that he's doing exactly what I have to do: do jokes about all sides to be perceived as "fair," but the anti-Bush jokes are all based on stale "comedy templates," like "Bush is dumb," "Cheney is really in charge," etc., that nobody really believes anymore. Meanwhile, his jokes about the left, like ours, are much sharper and based on actual, up-to-the-minute quotes and events. That's because liberals roll out of bed every morning (or afternoon) and go to work on their one and only job: creating raw material for us comedy writers.
HA!