Does anyone have any good studies on how and why identity politics (not just left, but all politics relating to identity) matter within American politics? Or about disenfranchisement from the political system? I'm about to write a large essay on the US left and identity politics and I need some lib-friendly sources to refer to.
I can't help too much but maybe throw intersectionality into your pile of research topics. That would give you some information on how identity fits together.
Try this:
https://americanstudies.yale.edu/sites/default/files/files/Keyword%20Coalition_Readings.pdf
It's about identity politics from a black feminist socialist perspective. So that may help shed some light on an application of idpol.