I have already put forward the idea that separating from place is associated with more liberal politics. I imagine there is also significant overlap between political liberalism and people who are strong advocates of identity politics. It is risky to combine associations - 70% x 70% ˂ 50% after all.
Nonetheless, I will hazard the guess that these two also overlap, which is an irony. The folks who have separated themselves from "my people" in a physical sense are the ones who are most concerned about what has been done to "my people" historically. I don't just mean African-Americans by any means when I say this. They may be down the row. I was first thinking of two gay men getting outraged about how Alan Turing was treated (which I will snarkily note they had known nothing about until the movie came out a few years ago) plus the comment thread of an article about the same thing. I know, I know, comment thread. Not a fair measurement of anything. Still I think this is common in most of the identity communities, and this was one that struck me most oddly. They were angry that one of their own was badly treated. He was badly treated, but the intensity of identification is curious. He lived in another era, in another country, doing a job that most people can't well understand. They feel a kinship with him because he had similar sexual attractions.
I offer the following. We used to identify much more by region, but as Americans keep increasing their internal migration decade after decade this continually weakens. New Yorkers still see themselves as a group apart, southerners still do (though the broad region is holding on as a brand more than individual states), Appalachia still does but is waning. New England is a redefined brand as "liberal places" now, and Yankee* as a point of identification is defunct, possibly because it is entirely at odds with the new definition. Who else? In church I will still hear people identify as midwesterners, not so much by individual state anymore. People will readily tell you they are "from California," but seldom that they are Californian. Texans will still say they are Texans, but half of Texas seems to have come from somewhere else it seems. Describing where one is from is more of a story now - my wife comes from A, but her parents grew up in B. I lived in both C and D growing up, but my parents' families lived in C for generations. Most recently we lived in E because we went to college there and got jobs there right out of school.
Also, people would identify by their (usually European) ethnic group. That was the world I grew up in, in a mill city with many Greeks, French-Canadians, Poles, Irish, Swedes, Germans, and a few of just about anyone else who came to America at all. Jews, African-Americans, and Hispanics identified equally by those current categories and their immediately preceding residence, usually New York. (That is tactically bad with Yankees, BTW. It slows your acceptance. They should have said Connecticut.)
The third previous identifier was religion, but fewer people have even a nodding acquaintance with one these days. Even among those who have a place of worship, they may have been raised in another confession, or been in in a different denomination at their last address. The old identifiers recede, so we must have new ones. Those who tell us that these previous ways of viewing ourselves have been transcended in favor of all being one humanity, I observe that it hasn't worked out that way. We just find new ways to divide ourselves into Bear Tribe, Eagle Tribe, Badger Tribe, Fox Tribe. The academic conceit that we need to have Others to exclude misses the point. We like to have Us'n's, and that doesn't work well with big numbers. For big numbers we can only have allies or annual ceremonial gatherings.
*To foreigners, a Yankee is an American
To Americans, a Yankee is a northerner
To northerners, a Yankee is a New Englander
To New Englanders, a Yankee is a rural person from VT, NH, or ME.
To rural northern New Englanders, a Yankee is "someone who has pie for breakfast." Note that this is usually not a fruit or sweet pie, but one with meat in it, such as minced game, chicken, salmon, or ham related to the pork pies of Quebec. This seldom happens anymore. We do still have some cheap bastards, though.