I think that Kerwick is right that Obama has a vision of an America that would be better than what we have. He wants to do what he can to replace the latter with the former. Osama Bin Laden also has a vision of a “better” America, one that has accepted Islam and submitted to the Caliphate. Hitler and Stalin also had their own visions about what would be best for America (and the rest of the world), submission to Nazism or Communism. So, in a sense, each of these leaders wants to bring about what he thinks is good, and, in that sense, none of them has evil intentions. But each sees the versions of the good that conflict with his own as evil, as something standing in the way of what would be for the best.
What the American experiment brought to the fore was not so much a new version of the good as a focus on process. No matter how convinced you are of the truth of your vision of the good, you must convince others to willingly accept it, and cannot impose it by force. Government must secure the consent of the governed.
Ego maniacs like these don't give a rat's rear end about what's 'best' for anyone else. They think about themselves only.