Comparing current politicians and policy to 1920 Germany sounds good on paper, but back then most things happened in a bubble. I'm not talking about world war but the events that led up to it. For example, Europe being in all out war and the US still considered it, not there problem. I mean most nations at the time didnt even find out about concentration camps till we got into war torn Germany. Not to mention most jews loaded up to go to camps willingly with the promise of work.
For those type of events to happen today would be almost impossible.
Lets say on januray 6, 2021 the rioters did end up killing half the senate, trump stayed in power and the military leaders backed trump and imprisoned anyone who disrobed direct orders.
How long do you think trump would stay safe? Do you really think they can round up minorities and "undesirables" and tell them some story. How long before cities like Chicago, LA, New York and other major cities decide to set up a resistance, let alone people in the military going a-wall and other nations stepping in. Besides nuclear war, the biggest deterrent would be during this "civil war" countries like china would probably invade at the right opportunity. In any scenario the US would be doomed and for what? Millions of white and minorities would suffer for a small minority. With the small minority being old white guys.
Could it happen? ..Sure but the outcome would most likely mean the end of the modern world.