Seems like it'd be easier to explain why he seems like a Nazi (literally in uniform with a swastika armband and all) than to keep asserting that it's obvious.
Also is that last panel supposed to be a Stonetoss face?
I think the point is that if you try to show them the "armband" such as "hey here's this guy literally saying the jews should be eradicated" they refuse to look
I can have my moments of being that guy. "Obviously a Nazi" is less persuasive than "literally saying Jews should be eradicated" when it comes to believing they're a Nazi.