Bush's actions over the past four years are those of a person with a startling lack of self confidence, someone who's afraid that even a fleeting contact with an opposing idea will deflate him completely. Deep down Bush knows perfectly well that the facts don't always back up his instincts, and that's why he avoids them. He's afraid he might change his mind
Regardless of whether or not Drum has the right interpretation or not, U. Michigan Professor Juan Cole makes an eerie comparison between Bush and Mao Zedong of the Chinese Communist Party. Cole is not a radical lefty, he's actually a relatively sober commentator. It's a long post, but worth reading.