I think it is a product of raising stakes as wall between the public sphere and government control collapses.
Norms around free speech and free behavior been eroding for decades. Now that they are gone, each side sees it as an existential struggle. In an existential struggle, it makes sense to sacrifice any values you had because the alternative is worse.
e.g. if there is going to be a oppressive government, you want one that will oppressive others for your benefit.
e.g. even if you don't want a race war, if you are convinced will be one, you want your side to win.
You see similar situations in national wars (strike first before they strike you), or prisoners dilemma where both parities defect.
Society at large is an unstable solution to the prisoners dilemma
built on trust.
IMO we got here from erosion of trust in government and society in general.
Norms around free speech and free behavior been eroding for decades. Now that they are gone, each side sees it as an existential struggle. In an existential struggle, it makes sense to sacrifice any values you had because the alternative is worse.
e.g. if there is going to be a oppressive government, you want one that will oppressive others for your benefit.
e.g. even if you don't want a race war, if you are convinced will be one, you want your side to win.
You see similar situations in national wars (strike first before they strike you), or prisoners dilemma where both parities defect.
Society at large is an unstable solution to the prisoners dilemma built on trust.
IMO we got here from erosion of trust in government and society in general.