Nearly right with identity politics but it is any sort of identity, not just gay/straight/white/black/a woman. Social class, locality, occupation, religion, etc. It's any sort of pandering that will associate X political ideal with Y identity. So identity politics can be 'enlightened smart people vote left, bigots vote right'. Or for you own country, 'Gammons vote Tory'. I can almost say it's a way of justifying of your own preference while putting down other's.
Identity politics isn't a new term