I am fascinated by the question of what makes liberals tick. This blog will refer you to a thoughtful article by Larrey Anderson at the American Thinker that suggests that liberals are not really insane.
I don't know. Liberals seem to be insane. Their talk and apparent thought patterns appear to be insane. Walks like a duck, quacks like a duck. The jury on that is still out for me. The article is well worth the read, though.