I realized today that identity politics is probably just one facet of a larger movement against the cultural mainstream. I realized this when I was thinking about the difference some draw between "liberal" and "radical" approaches to issues of gender, race, or sexual orientation. One of the features common across so-called "liberal" approaches—usually as they're portrayed by their "radical" critics—is a desire to demarginalize a group, usually by acquiring the rights that already belong to the non-marginalized groups (the "mainstream").
The particulars of this aren't that interesting to me. The scholarship on these issues is diverse and nuanced, as contrasted with views expounded by individuals on the internet who throw around terms like "radical", "liberal", and/or "identity politics", which seem coarse by comparison. What interests me is this notion which seems to have entered the zeitgeist at some point after the 60s which equates being radical with being part of a subculture or marginalized group outside of the mainstream. After all, if you go back 100 years, the opposite was the case. Radical political and even cultural claims were not founded in opposition to universalism but were understood as extensions of them. It was the conservatives and reactionaries who opposed to this the rights of the individual or the group.
Nowadays the situation is reversed. But I don't think this is a sui generis phenomenon. It appears to be part of a larger trend. You can see it in music, too. There was a vibrant mainstream in music up until about the mid-70s, and then it started to break apart into different genres. There was no such thing as the "mainstream". You could hear almost any kind of music there was in the middle of the FM dial (at least music produced by whites). The mainstream was formed from the opposition to it of the subcultures which became hip hop, hardcore, alternative, etc. The economic, material component to this was essential, of course. "Selling out" meant compromising your artistic vision for money. But it was more than that, because it was a general way of having a style and being an individual. To be an individual meant being in opposition to the mainstream.
There are probably more examples than this, but these are the two that leap to my mind.
Personally, I'm not sure whether it's a good thing or a bad thing that we now have subcultures in opposition to a mainstream. I don't know whether it's good from an artistic perspective. I don't know whether it's good from a political perspective. It raises a lot of problems. But I don't fall in the "cultural critic" camp. I don't believe we have passed out of a Golden Age into a time of decadence. I think some people in the United States and Europe have undergone a particular experience or set of experiences which have made it seem all-but-necessary to them to embrace a particular model of individuality. That it's the opposite from the model of individuality held by radicals 100 years ago is not good enough reason to reject it. That our current age is beset by innumerable problems is not good enough reason to blame them. I'd be interested in know what caused it to happen and what the general telos of the thing is, though. It might seem odd to look for the natural trajectory of something which seems fragmented and inward-looking, but if I'm right, it is, in fact, a very general trend shared across subcultural lines. You are being an individual just like everyone else—but that might not be a bad thing!