hitler was seen to be pretty crazy to most "moderate" germans too and he wasn't voted in as the führer with absolute power. he slowly worked his way up in popularity until he became chancellor. then he worked to slowly build up members of the NSDAP into positions of power until no one could oppose him. then he began suppressing the opposition.
the lesson about hitler in germany is not, "don't vote in an extreme dictator" the lesson about hitler is that a person can assume power legally and still end up with total control without the will of the people.
you "promise" to stand up to trump if he becomes this. but by the time you realize what's going on. it'll be too late.
now i'm not saying trump is going to become hitler. the reason everyone is scared now is because he is following similar blueprints to hitler or other fascists. most of the time these type of leaders just become any other "normal" leader and do their term and let power go democratically and i honestly hope that happens because that's the best case.
but if he goes through with everything he promises. it'll be very scary. trumps call to south korea president assuring her that us forces would remain was very assuring for the stability of asia, so i have some hope.
this is almost a version of the boy who cried wolf. too many people have cried hitler and now no one believes it or just dismisses it outright.