Here is an article about George Lincoln Rockwell, America's last "Nazi":
My first wife had an uncle (not a blood relative) who was a card-carrying member of the US Nazi Party. He also belonged to a flying club which included Hitler's pilot Hanna Reitsch as one of its members. This was back in the 70s. I thought the guy was a nut, and everyone agreed with me.
US Nazis were an extremely small fringe group then, and I doubt they have done anything except shrink in the interim. This latest "Nazi" scare is total BS.