I think you hit it right on the head. What I'm wondering now is: What leads to this association of politics and identity? Is it a product of our culture, upbringing, is it human nature? Is it that modern life has so little avenue for people individuating? Maybe it is filling a void.

One thing that strikes me as key to this polarization is how pervasive are some generalizations we make today and how the individual is lost when we make them. I've seen racists make the comment "Black people are ...." (won't repeat that here) but then I see activist say "Black people are (ex. disadvantaged.)" Are there no quite privileged black people? (millionaires, billionaires, etc) Don't lower class people face a pretty similar set of challenges no matter their skin tone? When you look at it, both arguments are generalizing equally as aggressive. My question then is: are all generalizations wrong or only some?

I think this process of grouping people has ome currents of thought tend to generalize two aspects to it, people who group other people when making statements and people who in some search of uniqueness, group themselves into it? As a non-American, coming from a very heterogeneous country I find it hard to follow how many people will self-identify so readily with a group and in the process lose some of their individuality. Maybe I speak from "privilege" as someone who due to upbringing and origin, felt a quite distinct individual, so I cannot say for sure. I just think this currents of thought harm more by dividing into groups and with many individuals satisfying their need of identity there.

Personally, I think the US in particular is prone to this kind of thinking because the winner-take-all system incentives a dualistic, all-in approach. Thoughtful reflection does not win elections: riling up the rank and file does, including demonizing the opponent. More parliamentary, proportional systems encourage cooperation and collaboration among opponents

As for generalizations, the English language has an unfortunate construction that allows speakers to be ambiguous about their intent when making a generalizing statement. For example, "Men are violent" is a misleadingly meaningless statement. Does it refer to some men? To all men? Is it referring to the fact that men tend to be more violent, statistically, as a group? That assertion is ambiguous, but the always-truthful qualification "some" sits uncomfortably close to the always-unfair and bigoted "all". Bigots of all stripes rely on this ambiguity.

I don't think generalizations are bad necessarily, but to honor the dignity and diversity of individuals, it's vital to avoid this ambiguity, and to always be explicit about the generalization that you're making, and then your statement can be evaluated for what it is, pro or con. E.g. Instead of a Men are violent say what is meant, clearly: Some men are violent. In general men are violent. Most men are violent. All men are violent. Now at least we have a statement that can be agreed with or disputed, instead of motte-and-baileyed