I'm over-commenting on this thread, but this is a pet topic of mine. A controversial observation of hers was that both fascism and communism were mere national movements, limited to their nation states, where what distinguished totalitarianism as a new form itself was using those nations as stepping stones and vessels for global domination. She gives some examples of totalitarian leaders rejecting both of these ideologies as not sufficiently ambitious, after using them as stepping stones.

My own interpretation is that it begins by inculcating an identity of shame and powerlessness, which respectively create the necessary righteous cruelty and infinite appetite for power to get a totalitarian movement going and neutralizing opposition to its aims, e.g. "for good men to do nothing." It is systematized, and simple enough to iterate and scale, because what it truly was is directed chaos. Defeating it is also simple set of rules, and is in fact related to defeating loneliness as well, but that's a much longer topic.