Colorado and NY too. Colorado seemed especially off plot to me.
Colorado was a nexus in The Neutral Zone. So of course there was a concentration of Undesirables there. Including if you remember, blacks, Muslims, the albino shoe-shine kid, etc. Of course it would not resemble the real-world Colorado.
I actually didn't find the BCR overly preachy, if anything it was un-realistic in it's ideology. In a world where blacks went straight from Jim Crow to concentration camps, I would expect such a movement to arise, and desiring an ethno-state would also be realistic. And aligning with communism is also realistic in a world that never saw the Soviet Union yet (it parallels HoChiMinh actually, who actually admired America quite a lot, including Thomas Jefferson and French revolutionary thinking; he just thought communism was a next step forward which is more understandable in a world that never saw late-stage communism, such a MitHC). The BCR were portrayed as wishing to right the injustices of the past with more egalitarianism. In reality, I think it's more likely that such a movement would be more exclusionary and closer to the Black Panthers.
Overall I think the portrayal of the Nazis was probably over done. They really would have taken over Europe if they had the bomb. They would have wanted to take over US, but unless they had nuclear subs, I don't think the US would have folded so quickly because it still takes reach to field nukes. It's more likely that Nazis would have taken over Europe there would have been a nuclear standoff between US and Nazis decades later once cruise missiles and nuclear subs came around.
Also if the Nazis did take over US it would have refined its propoganda. The Master Race thing just wouldn't have worked in the US. We are led to think that they exterminated all Jews and blacks in the US and I think that's highly unrealistic. It's much more likely they would have done something like the segregated South.
