He's not a serious candidate. He thinks he is, the truthers who support him think he is, but...nah, not so much. He's kooky, cranky, and sits on the same side of the 9/11 aisle as RosieO, that goofy guy on Hannity and Colmes, Sean Penn, etc.
Check out this from Ace of Spades (if you're offended by language, skip the comments section). He pretty much nails the guy.