It is a law of history that fundamental ideas dictate the leader's and the masses' view of what constitute the practical. Ideas determine the course of history of a nation, a nation's frame of reference, code of values, a people's character and culture, and major decisions. The same fundamental bad ideas that led to nazism are those of leftardism: irrationalism, emotionalism, altruism, collectivism, statism, and socialism.
Netflix has a series on now that details the operations of the Einsatzgruppen in Russia and the Baltic states.No sane person would ever compare anyone with Hitler after watching that.