On the fact that his own work was probably not terribly effective at causing change:
"It's not even preaching to the converted; it's titillating the converted... I'm fond of quoting Peter Cook, who talked about the satirical Berlin kabaretts of the 1930s, which did so much to stop the rise of Hitler and prevent the Second World War."Jon Stewart made a similar point on one of the last showings of the Daily Show this week. I can't remember exactly what he said, but the basic point was that for all the popularity of the show, the world is still totally messed up -- in fact, more messed up than when he began.