Identity politics isn’t really about being able to identify as something you’re not - that is the added confusion of ‘trans’ ideas/Queer Theory. When I think of identity politics, it is more about navel-gazing and narrowing down who you are according to all the sub-classifications. Like in the 80s when people used to take the piss out of lefties announcing themselves as ‘a disabled Black lesbian’ or whatever. With ‘trans’ ideas, a straight, able-bodied, white man can now ‘identify as’ a disabled Black lesbian. It’s ‘trans’ identity politics.
I think the confusion we’re getting in this thread is the conflation of the ideas of ‘classification’ and ‘grouping’. With ‘classes’ you are thinking “how are we going to slice things into smaller parts so we can see how it works?”, with ‘groups’, you are thinking ‘how are these individual elements/people, working together and interacting as one group?’.
So you can stand on the corner of the street and classify people by height as they walk by, and classify people as ‘below 5’2, 5’2-5’10” and above 5’10’ - although there maybe some commonalities about the way these three classes navigate the public space, they can’t be meaningfully ‘grouped’ together, because they don’t interact or work together, they are just the way you decided to slice the pie when you were gathering your stats.
So you can analyse the commonalities of, say, ‘white men’, but it will only give you the broadest, sweeping generalisations to work with. A first generation Lithuanian man in Lewisham can’t be meaningfully grouped with King Charles, since they live and more in entirely different social eco systems.