You note Weimar, and I recall that in the period leading up to the Nazi takeover German high school students were taught to despise their Republic. By the nineteen thirties Germany had a generation of young adults disposed to despise democracy and accept totalitarianism.
Actually, “antifa” are the direct descendants of the Red revolutionaries in the Weimar era who rioted against and murdered their adversaries. Their violence caused the Nazi Brownshirts to become seen as their most effective opponents and facilitate the rise of Hitler and the destruction of democracy in Germany.