Remember THE SNAKE? TRump recognizes a snake when he meets one.
That’s right. I always liked the snake story, but no one tells it better than Trump.
I've got to think that in his years in the New York construction business Trump saw a much wider range of human behaviors than the slugs in D.C. do - toadies, suckups, bullies, parasites, etc. Add that to, IMHO, an innate ability to size up people almost instantly and he's tough to bluff.