Regardless of whether or not Trump wins or loses, he’s going to become the Hitler of Presidential politics. He (probably) won’t become a dictator and kill lots of people, but he will become the new low benchmark by which all other bad Presidential candidates are judged.
I further predict that Trump denialism will also become a thing, just like Holocaust denialism, and calling a politician a Trump will be subject to a Godwin’s law scenario. In 10 years or so, people will be saying “Oh, Trump wasn’t that bad.” We’ll need a memorial and video archive to keep the memory of just how low Presidential politics can go and remind us to never, ever go there again.