The Poorman Institute nails it with a brilliant analysis of political discourse: http://thepoorman.net/2008/10/13/observations-on-recent-trends-in-political-discourse/
"I’ve noticed, recently, that people who disagree with me are stupid and dumb. I can’t really believe they are as stupid and dumb as they seem, so I think they must be crazy as well.
Why are they so crazy? Well, any discussion of this would have to begin with how stupid and dumb they are. Imagine if you were so stupid and dumb that you actually disagreed with me, even when I was totally right? That would be enough to drive anyone crazy.
But the flip side of this requires looking at how smart I am. I’m pretty much right about everything, and with each passing day, as more and more of my predictions are born out by events, the incredible differential between people who disagree with me and are stupid and dumb, and me, who is wise and correct, becomes harder and harder for these stupid dummies to bear. And it drives them crazy."