"Why don't we acknowledge that political belief is also an aspect of human behaviour in need of external control?"
- which would have be fine if you were creating a strawman to knock down. 

But no, you killed the strawman of Nazism much earlier. They are a fringe that can be safely ignored, recognize that as a fact.

Sure, you can try shrink the size of the Overton Window so that only the breeze from political ideas you like can waft through. But realize that will not work for the majority of us.