I'm not sure how many people here caught Peter Boyle (Frank Barone from Everybody Loves Raymond and Frankenstein's Monster from Mel Brook's Young Frankenstein) on Mind of Mencia the other night. Mencia has him on from time to time to offer cutting little quips about cliche cultural items. The video segment is up on their website and, I don't want to ruin it for you, but please do watch it to the end (there's a mean Bush dig a'coming, I promise). Mencia's show is very race-oriented, and goes to some of the most politically incorrect places on the comedic spectrum. And in a lot of ways, it's frat-boy humor or, at the very least, non-partisan sniping (though he is one of the few people I know that showed the Bush Middle Finger video on the air). But as far as I am concerned, when you can find that dismissive a joke about George Bush's voting base on a show like Mencia's, that speaks volumes about his popularity and credibility.
http://www.comedycentral.com/sitewide/media_player/play.jhtml?itemId=61502&ml_collection=&ml_context=show&allowMotherload=true&ml_gateway=&ml_comedian=none&poppedFrom=_shows_mind_of_mencia_index.jhtml&EDIT: In case they change the listing, it's the Bumper Sticker segment.