Identity politics is something else, a claim of authenticity based on biological or ancestral status, and a rejection of arguments made by those with the wrong status. thus "as a woman, I know bla bla, and you, a man, have no way of evaluating what I say." Identity politics is related to nationalism, and like nationalism has no necessary (although maybe sometimes a contingent) connection with left politics. After all, anti-choice women can also speak "as women" and claim that their experience entitled them to credence, leadership etc. Clarence thomas made very skilful use of identity politics during his confirmation hearings, and received much black support on the basis of race alone,ie that his poor race-inflected background would lead him to 'do the right thing." People discovering their "roots," getting all involved in their (often semi-imaginary) heritage, their Scottishness, jewishness, Canadianness (margaret Atwood is particularly silly on this), adoptedness, Sunpeopleness -- that's identity politics.
"class" politics can also be identity politics. I>E> the "working class" is conceived of as a unified grouping with special claims to knowledge and a tribal culture (special food, music, pastimes) that mark the partaker as superior. I would say, for example, That Michael Moore practices a kind of white-working-class identity politics. He counts as working class, even though he's a millionaire, an entrepreneur, a celebrity. I count as "a blue blood" because I live on the upper West Side. of course, he also lives on the Upper West Side...
What is so infuriating to me is when women's LIBERATION or the LIBERATION of people of color are treated as matters of "identity" (ie a psychological luxury) when they are matters of rights, justice, fairness, equality. Abortion rights, for example, are not about women withdrawing into their own little world, but about women being able to participate in the mainstream of society. Affirmative action ditto.