Why is Howard Dean riding Mrs. McCain?

If Bill Clinton and Michelle Obama are fair game, isn't Mrs. McCain also? What sets her apart? Conservatives don't like it when their own tactics are turned on them! I don't really care what Mrs. McCain is worth, but some of her money could easily end up in John's pocket, which if he wins, would be a good investment for her interest in being "first lady". That is a remote possibility, but it is a powerful position.