I have NEVER understood this. This is pretty random, but I just saw him pop up as ESTP on yet another site and HAD to talk about it.
Okay, so he was very active and into adventuring. You don't HAVE to be an SP to be into that. I guess what I'm saying is that is such a small detail to base his typing on. Everything else about him, from his policies to his visions, seems very blatantly NT. Here's a quote by the man himself talking about his childhood. Sounds a lot like an NT kid.
"As far as I can remember they were absolutely commonplace. I was a rather sickly, rather timid little boy, 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! It was not until after I was sixteen that I began to show any prowess, or even ordinary capacity; up to that time, except making collections of natural history, reading a good deal in certain narrowly limited fields and indulging in the usual scribbling of the small boy who does not excel in sport, I cannot remember that I did anything that even lifted me up to the average."
Another reason I feel he was an NT is he was always thinking about the future. Rather than dealing with issues in a here and now style like an SP (such as JFK) might, he was always planning ahead, with a great amount of adaptability, ways to secure a vision for the future. He came up with visionary ideas that when compared to the ideals of his time came off as very radical. He was the first to propose the idea of a social insurance (an idea that later became social security under FDR) and when first assuming presidency, went against his previous Republican president's views of smaller government involvement, and set in motion plans that would regulate big business. He was also the first to ever invite an African American to the White House.
Nothing about the way he thought, planned, and handled situations seems SP to me. He challenged convention, rather than wanting to lead the way others had before him.
I'd say he was most likely an ENTP 7w8 or 8w7. I see very little to no S dom behavior in him. And from how I've heard him described, he sounded very Ti/Fe. He was supposedly a super charming guy in a crowd and hard to read.
Well, that's my rant haha.