To prove your point no original nazi is needed, there was that nazi rally recordings of which are avaliable.

https://en.m.wikipedia.org/wiki/1939_Nazi_rally_at_Madison_Square_Garden

When USA government took a wind of their future involvement in this war, they found that adoring fans of Hitler aren't what you'd like to gain popularity at home while sending boys to Europe to catch the fucker. I don't know the morals of politicians who took steps to tone down the Hitler-fandom, but the first layer of this onion is that - it was against the geological goals of the US - to enable that strain of nazism - at the time. Were they allowing the same populist mythology about the US to prevail, did american soldiers thought themselves superior to others, with their democracy, founding fathers, ammendments? Probably. But the original sin was erased in a public memory as the Axis-ov-Evil felt, the Cold War started and the US, especially, saw a boom in it's prosperity.

But to counter your pov, I'd argue, there aren't particular 'people like that', but social conditions of frustrated masses gullible enough to follow populists adressing their emotions, establishing their past as great and promising the return to that. These notions are just copycats of one another. The healthier the society the less we see the monsters constructed and enabled by it's failures. There was some quote of Stephen (I created but abandoned my bluesky) King that in order to kill you'd need to have a bullet in your heart, and I believe that most deranged shooters who went on a probably suicidal killing spree against their own kind didn't have that bullet initially, but they've been conditioned by the times like late Wheimar Republic, late Soviet state, and, probably, late America, if it won't get of these rails.