Hitler had a huge party of supporters behind him that he spend a decade gathering around him. Trump on the other hand is much more of an one-man show. One of the biggest role of the president is making personal choices and there simply no comparable pool of talent. Under a Trump administration someone like Chris Christie who's a long-term friend of the Trump family is likely going to get a post in his administration.

When it comes to totalitarism it's a mistake to assume that the past will repeat exactly the same way. It's hard to believe a US government would simply torture random people with Arabic names intentionally just because they have Arab names. It's more likely that privacy will get completely eroded. Today we have face recognition that's strong enough to hook up all camera's on streets to it and get general movement profiles. Forbidding encryption would also be on the table.