Identity politics is the conflation of political ideology with personal identity, typically resulting in arguments of the general form "I am [an] X, and therefore Y is part of my identity" when defending Y against criticism.
It is based on the idea that people do or should have fixed sets of beliefs about what social policies are best, rather than sharing the universal ethical concerns of minimizing harm and maximizing collective benefit – and that those beliefs derive mainly from their membership in certain groups.
Reinforcing the idea that beliefs derive mainly from group membership rather than from examination of evidence also reinforces the idea that no set of beliefs is better (more accurate, less harmful) than any other, thus providing cover for highly irrational and even clearly harmful tribal beliefs to be regarded on an equal footing with the scientific consensus.
- Conservapedia "Identity politics is the basing of one's political and sociological viewpoint by claiming membership in some "oppressed" group and then constructing most of ones lifestyle and identity around their supposed membership in this group. [...] closely related to political correctness and multiculturalism, and in some cases to postmodernism."