He's certainly liberal and enjoys, perhaps as much as I do, making fun of Fox "News", but I still consider Stewart to be a voice of reason. He points out the outrageous aspects of everything happening in the world around us.
Unless you spend your days locked in a basement watching CSPAN and every cable news network around like Stewart's staff does, you can't possibly discover all the golden sound bites that fall through the cracks.
The Daily Show performs the "watch dog" function that mainstream media is supposed to handle. That job once was ably performed by network news anchors and major writers at big time papers, but the number of old-school reporters is dwindling and the archetypal reporter isn't nearly as prevalent as it once was.
Ultimately, that was just a long-winded way of saying watch this clip. Jon Stewart rules.
I'd encourage checking out this video here of the second segment of this show. It continues the points made in the first one.