"My biggest concern is staying out of war so I voted for the guy I think is Hitler."

Read!?

Ha!

The thing to keep in mind about idiocy is that idiots make mistakes, a lot. At the same time, those mistakes are usually small-stakes affairs (it's hard to make big mistakes with no money and/or resources) and are usually recoverable. The idea that their mistake could affect so many others simply does not happen, because that's not how things typically work.

Did he not read the part where Hitler genocided Jews, Europeans, and the disabled?

That's the thing though — Hitler didn't run on a platform of genociding people, he ran on a platform of economic improvement. Weimar Germany was economically depressed and many average people and families were suffering from unemployment and financial hardship while the rich were relatively unaffected and enjoying themselves. Hitler promised to change that (and in all fairness, he did). The genociding Jews part came much later.

Hitler was in charge of Germany for 11 years (1934-1945) — the war didn't start until 1938, and the holocaust only began in 1942, so the voters DID end up getting at least 4 years of relative peace and prosperity. Also, keep in mind that Hitler was 45 years old when he became chancellor, meanwhile Trump is 78, meaning even if he manages to finish his second tenure successfully, he'll very likely simply be too old by the end of it in order to continue, which makes it somewhat unlikely that he'll attempt to stage another coup in order to remain dictator for life.