If arm length was an indicator would probably go with Obama having the largest member. Have you gotten a good look at McCain arms? He's built like a freakin" Tyrannosaurus Rex! Despite the difference I think that both McCain and Obama are probably boring in bed. If it was my choice I'd have to go with Clinton or even Bush as a better screw. I think they're both closet freaks.
Did I just say that? Oh no, I'm losing my damn mind!