How Do You Deal With Evil?

In my study of the history of World War II, many writers said that Hitler and his inner circle, in their private lives, were very sociable and jocular, and loved attending the opera and attending symphonic music concerts. If we did not know about the depravity of their policies and deeds, many would say these were pretty nice, cultured people. Does being nice privately, excuse and make acceptable, those who are supportive of global hegemony, involving the gratuitous bombing of civilians and their infrastructure, and other murderous policies? Do we disregard the evil they are supportive of, and base our approval on how nice they are personally and privately? I think one has to look at the total person and decide if the policies they support disqualify them from being considered good people, and are therefore, unworthy of our regard, respect and friendship. If most of us would apply this standard to an extreme case like Hitler, we should certainly also consider applying this same standard to those around us who are supportive of the evils of this current administration and it's allies.
I was taught as a young person, and I still believe, if you want to know what kind of person someone is, a good starting point is to consider their personal political beliefs, and what causes they support.