Central to Political Correctness Is the View that Western Society Has Been Dominated by "the White Male Power Structure" and Everybody but White Heterosexual Males Has Suffered Repression

The term "political correctness" made its way into public consciousness through an article by Richard Bernstein in the New York Times (1991). It referred to a strain of postmarxist leftist thought in which the struggle between economic classes has been replaced, as a primary ontological framework, with a more differentiated set of oppositions based on such differences as sex, race, and sexual orientation. Thus, as Bernstein put it:

Central to pc-ness, which has its roots in 1960's radicalism, is the view that Western society has for centuries been dominated by what is often called "the white male power structure" or Patriarchal hegemony." A related belief is that everybody but white heterosexual males has suffered some form of repression and been denied a cultural voice. 

He added that, to many of those concerned with this phenomenon, the disturbing thing about political correctness ("PC") has not been the content of its ideology, but the principle of argumentation that it has employed:

 more than an earnest expression of belief, "politically correct" has become a sarcastic jibe used by those, conservatives and classical liberals alike, to describe what they see as a growing intolerance, a closing of debate, a pressure to conform to a radical program or risk being accused of a commonly reiterated trio of thought crimes: sexism, racism and homophobia. 

--Howard S. Schwartz, The Revolt of the Primitive: An Inquiry into the Roots of Political Correctness (New Brunswick, NJ: Transaction Publishers, 2003), 113-114.