Maybe companies should adopt a practice of only hiring middle-of-the-road rational, calm, level-headed people, instead of people who are far left or far right?
Problem is, how do you know? It's not like people talk about their leanings during technical interviews. I'm sure a set of conventions and tactics will evolve over time to handle this.
A background check that includes even a cursory review of the candidate's public social media presence would probably go pretty far in terms of weeding out the most extreme right or left wing people (who often tend to be vocal with their viewpoints).
There's a reason why I never post ANYTHING political on my public social media anymore. I keep all my controversial opinions limited to my alternate profiles.