"The mistake was not in the idea that his base was too small to elect him. The mistake was in misreading his second ring of supporters, those who cared little that the Klan, the Nazis and their ilk glorified Trump."

That's correct.  If the Klan and the Nazi's were to endorse the position that the Earth is round, I probably would not change my position based upon my repulsion of them.  I generally view ad hominem and guilt by association as logical fallacies.  You're a professor?  LOL!  Mental midget.