I agree with the sibling comment that post-WW1 was a different place, but I'll add that from the reading I've done Hitler and his cronies were so much worse at their stuff than the 'tactical genius evil' the Nazis are often presented as being.

So maybe it was just a matter of having enough of these 'dumb' types and and some of them learning over time? I could see that happening if the US keeps increasing the number of these types of people.