I believe he was successful in spite of his negative qualities, not because of them. What I mean by this is that we shouldn't worship his negative traits and spin them somehow to be positive qualities in a leader, such as some people have done. He was very much a human being. A highly-intelligent man and visionary in the right place at the right time, surrounded by the right people, making a lot of good, and a few poor, choices. Don't try to reverse-engineer his success so as to duplicate it.