Hmmmm must be scared.
What a wuss!
its probably more arrogant, childish and sinister than that, I betcha Deans reasoning for a no show will be that he dosn't want to appear on the same program as an Evil Brain-dead Republican Nazi, he will say he is better than that, and it would tarnish his image to be seen with such a low-life.
haha or you guys could be right, and Dean is just a chicken.