There's a loneliness epidemic (even before the *-demic words became used for something else...), my theory is that lonely people were looking for a tribe to feel a sense of belonging and found political tribes to be one.

It also seems to me people take a lot of political positions not because they believe it, but because "the other side" takes the opposing view. Anything the "enemy" likes, I don't support. But the root cause would be to find that sense of belonging. Or it'd be because of insecurity: if I think the other side have idiotic opinions, I can walk around having the smug feeling of supremacy, and hey, at least I feel better, right?

It's the same issue with second generation Muslim migrants in Western Europe who feel "lost" and then found Jihad, they'd start as troubled youths who were shoplifters, who end up in jail, find the charismatic hate-preacher/Imam there and then are inspired and find their lives' cause, which is sadly Jihad. IMO white supremacist terrorists go through the same motions.

https://www.youtube.com/watch?v=qlbirlSA-dc or a text that's the same idea (by the same guy): https://www.theguardian.com/commentisfree/belief/2010/jul/19...