Quite.

As soon as I hit the Send button, I asked myself whether there had been any Nazis who once might have been decent and capable.

Probably not, unless they were young and naive and got out by, say, 1935. And if they stayed (to protect themselves and their families and perhaps to "work for change"), they undoubtedly never got   where they could do any good.

I don't believe any of the members of the July 22 plot against Hitler belonged to the Nazi Party (I could be wrong). Nor, I think, did the General who refused Hitler's order to burn Paris.

So my original post should have read "...*sometimes* a leavening...."