Echoes of Weimar

Instapundit Glenn Reynolds writes about the Antifa violence in Portland, and elsewhere. His invocation of Weimar is telling, see his conclusion.

You don’t get Hitler because of Hitler — there are always potential Hitlers hanging around. You get Hitler because of Weimar, and you get Weimar because the people in charge of maintaining liberal democracy are too weak and corrupt to do the job. And there are a lot of those now, not exclusively in the Democratic Party.

Exclusively? Certainly not. Would you accept "predominantly" or a folksy "mostly?"