I also think Obama is an ENTP (with an outside chance of ENFP). Definitely P though. His appeals to emotion don't have the dramatic flourish that I imagine a good ENFP orator to use. I saw him interviewed saying how disorganized he is and how lacks attention to detail, that would hurt him without his more diligent staff members. Also he seems to have more a P attitude of laid back-ness and body movement.
I would say Hillary is an ENTJ. She's very machievellian and is known for aggressive handling and grudge holding when people piss her off. It's one of the reasons there is such a galvanized Republican (actual politicians) hate towards her. She really is more in the LBJ mold of getting things done (very J like). But sometimes ambition and stubbornness cloud her judgement. She has a habit of not adjusting to the flow of debate as well - a certain stiffness that seems J to me (which seemed evident to me in their debate the other night).