Don't you think it's worth noting that the clue is in the name with 'identity politics'.
It's grouping people together based on one - or a series of - characteristics, rather than what they are like as an individual.
So, for example, I'm sure not every Trans person thinks the same as every other Trans person. So why should they all be grouped together politically? Why should they all be expected to have a same belief/ideology? It's not beyond the realms of possibility to assume that they would, but isn't identity politics labelling them as having these certain beliefs?
I really do think identity politics is a horrid thing to use. It's not taking people for what they are. It's viewing people as a collective. So if you're expected to thing a certain way because you're black, then surely that's racism in action?