I forgot to mention in the below post: it's based on the idea that Clark has already offered the VP spot to Kerry and they are cooperating behind the scenes. Remember that Kerry wanted the #2 spot from Gore pretty badly in 2000, and was on the short list, which means that Gore's campaign already did the necessary vetting. (Because of the need for vetting, Dean could NOT have made a similar offer to Clark).
Clark's claiming Dean offered him the VP slot then sounds like classic Republican projection. If Clark says Dean offered the slot to Clark, it really means that Clark offered the slot to Kerry.