In a post last year, Eliezer discussed a useful paper exploring the many biases that affect how people process political information. 

Via this blog, here’s comedian Lenny Bruce making a similar point:

I would be with a bunch of Kennedy fans watching the debate and their comment would be, “He’s really slaughtering Nixon.” Then we would all go to another apartment, and the Nixon fans would say, “How do you like the shellacking he gave Kennedy?” And then I realized that each group loved their candidate so that a guy would have to be this blatant — he would have to look into the camera and say: “I am a thief, a crook, do you hear me, I am the worst choice you could ever make for the Presidency!” And even then his following would say, “Now there’s an honest man for you. It takes a big guy to admit that. There’s the kind of guy we need for President.”