answer:There were no Neo-Nazis in 1938, just Nazis. Here is some documentary evidence from the U.S. Holocaust Museum about contemporary American groups that supported the Nazis. There’s even a photo of the rally that you mentioned. Here’s an article about the German American Bund, which was a Nazi front group in the U.S. Fascism was not just “a German thing.” There were many latent or overt Nazi/fascist supporters in the U.S., Britain, France, etc.