Tourette syndrome? Who knows - we give names to such phenomena for the illusion of understanding 'something' about it. But we hardly comprehend the least bit about even the gross chemistry of brains.
Surely someone to be pitied not excoriated. Yeah the Nazi/Jew stuff is hardest to overlook, but if a diagnosed Tourette case said such - what then? Would we 'debate' him?
Drawing generalizations re 'chess' seems also pointless, from such one example. A simpler diagnosis might be that, obsession is not dedication. And a One-Note Johnny probably IS a bore to self as well as to a listener.
Peace for the poor bastard.
Ashton