Vox reports on a study of our polarization into blue and red nations, a study which seems to say that social bubbles on the internet aren't the big cause. Those with lesser access to the internet are more polarized, meaning especially the old geezers among us are especially partisan.
I can sort of understand that; although I don't interact with my high school classmates (I should but don't) I see what some of them post on Facebook and they're mostly on the right, the far right.
The person who ran the study suspects that polarization is " result of deeper divisions within American society" as the piece summarizes his views.
I wonder though. Maybe the bottom line on polarization is simple: it's fun. After all, affiliating with one of the parties provides people with someone to idolize and someone to hate, and an unending flow of stimuli to elicit feelings of hate and love.