Again, it's all a matter of perception.
There is no 'good' or 'bad' in history. For every "Good guy" there is a "bad guy", who is, more often than not, the loser. It boils down to the age old question and context: if you kill someone, does it make you evil? Depends on the why you did it. If you feel your life was in peril, then you feel you were justified and that you are the good guy in the situation - but I doubt the family of the person you killed thinks so highly of you.
People do Bad Things, but it is not our right to judge them good or evil - we can judge them against if they broke a law or not, yes, but that isn't the same thing.
Neo-Nazis perceive Hitler's behavior to be good and just. That doesn't mean the majority of the world cannot see those actions for the evil it was.
Again, perception. It ISN'T hard to say, yeah, he was an evil son of a bitch. Nazis will disagree. Midnyte can call Clinton evil, and people will disagree. Dar can call Bush evil, and people will disagree. But is anyone actually right - morally - in saying "Yes, this person has an evil soul" or "This person is evil". Answer? Probably not - it is not our place to judge these things.