Reason's Jesse Walker documents the growth of political correctness on the Right.

When I say "political correctness," I'm referring to an attitude, not an agenda. In some hands the term is a broad synonym for censorship and groupthink, qualities that have always been common across the political spectrum. Other times it devolves into a vague smear-term for anything left of center. I'm using it to describe a particular political posture: one that treats identity politics not just as an ideology but as a trump card, that maintains a rigid orthodoxy while regarding itself as subversive, that uses a series of contrived outrages to feed a bureaucratic machine. Each of those elements has infected parts of the right.