What I find disturbing on that tape along with "what" he said was "how" he said it. If I had been a 16 year old in that class that day I would have been seriously intimidated and frightened. It sounded more like a hellfire and brimstone sermon than a school lecture.
I wouldn't have wanted to be exposed to that even if the subject was Clinton and the Clinton admin. I don't think I would have felt that way if it was college, but not a sophomore class in high school.