US Authoritarianism

It sounds like you're missing the point that the "dark path" of extermination starts with casting people with brain damage as the enemy. Dehumanization is a Nazi tactic even when used by people who consider themselves antifascist.

Vote against Fetterman by all means, work to promote progressive goals. Research what kids of brain decay cause withering of empathy and how to restore it. But don't dismiss those who've suffered brain damage as a whole. And maybe learn to recognize assholes even when they seem to be on your side,like Fetterman before the damage stripped away his progressive veneer.