One aspect of this that fascinated me is Nazi Germany's "physics denialism" (?) — the reactionary response to the modern physics revolutions of the early 20th century. (I.e. the twin revolutions of quantum physics and of relativity). It was a much weirder response than simply an attack on physicists who happened to be Jewish humans. Fields of physics were conspiratorially labelled as having a "Jewish" character, and…
It was the same thing in mathematics. For example, when Edmund Landau defined pi as "twice the value of the unique zero of cos in the interval [0, 2]" (a very common definition) instead of geometrically, this was attacked as being "un-German" (even though you can obviously go from the geometric to the analytic definition and vice versa). https://institucional.us.es/blogimus/en/2017/03/pi-and-the-n...
The correct reaction is to identify people using this particular pattern and penalize them regardless of political or cultural affiliation. Especially if they're in your own tribe - you're the one in the best position to censure them.