Murder on the Right, Thunder on the Left

Someone—probably Hanna Arendt—says somewhere that fascism, at bottom, is a bid for the destruction of people for who they are, for being born into the wrong category or type of the human. Arendt's intuition here—I think it is Arendt—pertains to fascism in its essence and its fundamental appeal, its power to sway masses of people. It does not mean, of course, that fascism in all its murderousness is inclined to grant its political opponents, including those from outside the despised caste, or castes, any quarter. (I use the word caste advisedly. My thinking on these matters has been affected by Isabel Wilkerson's excellent book Caste: The Origins of Our Discontents. For Wilkerson, and I agree, caste, as opposed to economic class or even religion, is something one is born into and cannot leave, no matter how one's material circumstances might change.)
By contrast to fascism—again, I'm probably indebted to Arendt here—left-wing authoritarianism, AKA capital C Communism or Marxism-Leninism—not Marxism per se—seeks not only to destroy the capitalist class as such, its ostensible mission, but also to prevent or snuff out what it deems the wrong ideas; to destroy persons not for who and what they are but for what they might think or say.
I suspect that the contrast here is rooted in the difference between the respective psychologies of caste and class. Humans have been creatures of the tribe longer than they have been creatures of political economy. To put it another way, the tribal is rooted in a part of the human brain that pre-dates higher culture and probably humanity itself, and is no less powerful for it. Fascism does not concern itself overmuch with ideas, dissenting or not, because at bottom it is not based on ideas but rather fear of the Other, the foreign, the non-conforming. By contrast, capital-C Communists, not to mention most or all Trotskyists and probably a good number of Maoists, are concerned with dissension from whichever orthodoxy they hold, because ideology is their weakness as well as their strength. Fortunately or unfortunately, people's ideas or feelings about class-based political economy may simply not run all that deep. This is partly due to the fact that one's status in a given economy, unlike one's caste, might be subject to change.
The tragedy of all this is that communists have some good ideas, and, at their best, an astute assessment of capitalism and political economy at large. Fascists have neither. Which is why rightist rabble-rousers occasionally make leftish-sounding noises about economic elites as well as demonizing the educated and the intellectual; it is a matter of stealing the thunder of the left.