It's not really that surprising to me that this movement got the following it did. Institutional racism had flourished in our country (sad to say) since the end of the Civil War. Anti-Semitism was also by no means restricted to Germany. I don't think (although I admit I don't know) there was as big an anti-emetic feeling in the US as there was in many other European countries, but I'm sure there many who either didn't care or had sympathetic leanings. It is also hard to imagine what the perception of the NAZI party was in the world in 1938 without imposing our modern understanding of what the NAZI party was and what it did. I don't believe anyone in that day and age thought it was up to any good but the extent of its evil wasn't common knowledge either. Still, on the grand scheme of things there wasn't a huge following. The size of the group as documented in the article was perhaps up to 25,000 compared to the Nazi movement in Netherland which had a membership of 52,000 in 1936 (according to the knower of all things-sort of, Wikipedia. And the netherlands is a much smaller contry. Still, with what the NAZI party stood for (all one has to do is read Mein Kampf to see what NAZIism was all about) one in the party was too much!
Thinking about this made me think about the story I had once heard a black veteran tell. He was traveling on Army business and was in uniform when he stopped for something to eat. The eatery where he stopped made him eat in the kitchen. Though the door he could see two MP's escorting a couple of German POWs who had stopped to get something as well. He recalled thinking how screwed up that was that here he was, an American soldier, being made a second class citizen while a couple of the enemy sat and shot the breeze with their captors out in the dinning room. How screwed up is that?
I will see if I can get the source for that but I seem to recall seeing it on a History Channel special.