Obama: ENTP
Bush II: ESxP
Clinton: ENFP
Bush I: ISFJ
Carter: IxFP
Kennedy: ESFP
Lincoln: INFP
Washington: ENTP
I'm sure the ENTPs would love to claim Washington lol but I've heard some very convincing arguments that he's ISTJ. As far as I know, the only ENTP presidents we've had have been Obama, possibly Lincoln (most likely introverted, but a definite xNTP), and Teddy Roosevelt. Most say he's ESTP, but i don't buy it. There are so many things about him that say otherwise. He was always pushing innovation, even when it was unnecessary for a solution. heck, just this quote from his childhood paints him as more NT than SP:
"[I was] very fond of desultory reading and of natural history, and not excelling in any form of sport. Owing to my asthma I was not able to go to school, and I was nervous and self-conscious, so that as far as I can remember my belief is that I was rather below than above my average playmate in point of leadership; though as I had an imaginative temperament this sometimes made up for my other short-comings. Altogether, while, thanks to my father and mother, I had a very happy childhood I am inclined to look back at it with some wonder that I should have come out of it as well as I have!" -T.R.
Also, JFK comes off as more ESTP to me. I'd also label GWBush an ESTP, though ESFP is very easy to see as well. definitely not an N.