Ever since he burst on the national scene, up from obscurity as an Illinois State Senator addicted to voting present, his purported "likeability" has been cited as one of Barack Obama's principal political assets. Polling has historically shown that even as the public may disapprove his policies, they tell pollsters that they like him personally. To be honest, he has always left me cold, because I recognize in him the sort of figure I encountered many times in my academic career: someone who masks his lack of substance with a big smile, jokes (sometimes mean jokes at the expense of...