His (Trump's)  use—twice; once on social media, and then repeated in a speech—of the word “vermin” to describe his political enemies cannot be an accident. That’s an unusual word choice. It’s not a smear that one just grabs out of the air. And it appears in history chiefly in one context, and one context only….

This is straight-up Nazi talk, in a way he’s never done quite before. To announce that the real enemy is domestic and then to speak of that enemy in subhuman terms is Fascism 101. Especially that particular word….

-Chauncey Devaga in Salon.com