I think he was just a disappointed democrat who saw the truth about his party and couldn’t stand it. He finally saw the truth and could not bare being such a loser but could never be a republican either. He saw the rot for what it was and could not accept it. His mind was bent just enough that he could do what he did with no remorse.
I think in a week or two we will know a lot more but I doubt if much of it will be any more true than the magic bullet.