If it really was population density, it would be easy to discuss politics in urban NYC and very difficult/ rare in rural Wyoming. I don’t think that’s really the case. I suspect politics are more discussed in forums where there is more “psychological safety” where the consequence of saying a thing that others disagree with doesn’t cause a rift in the relationship (as evidenced by the “it’s hard enough for a parent to…
Psychological safety is another way of saying 'anonymous, cowardly trolls'. People say things they shouldn't when they believe they are anonymous. It's to our detriment.
Psychological safety is also a necessary part of intimacy in your closest personal relationships and is incredibly valuable for a company to provide their employees. It isn’t exclusively tied to anonymous trolling.