The level of ignorance is truly astounding. 
The term identity politics has been used in political discourse since at least the 1970s.
One aim of identity politics has been for those feeling oppressed to articulate their felt oppression in terms of their own experience by a process of consciousness-raising. For example, in their terminal statement of black feminist identity politics, the Combahee River Collective said:
"[A]s children we realized that we were different from boys and that we were treated different—for example, when we were told in the same breath to be quiet both for the sake of being 'ladylike' and to make us less objectionable in the eyes of white people. In the process of consciousness-raising, actually life-sharing, we began to recognize the commonality of our experiences and, from the sharing and growing consciousness, to build a politics that will change our lives and inevitably end our oppression."
Identity politics, as a mode of organizing, is closely connected to the fact that some social groups are oppressed (such as women, ethnic minorities, sexual minorities, etc.); that is, individuals belonging to those groups are, by virtue of their identity, more vulnerable to forms of oppression such as cultural imperialism, violence, exploitation of labour, marginalization, or powerlessness.
Class identity politics were first described briefly in an article by L. A. Kauffman, who traced its origins to the Student Nonviolent Coordinating Committee (SNCC), an organization of the civil rights movement in the USA in the early and mid-1960s.
Although SNCC invented many of the fundamental practices which currently make up identity politics, and although various black power groups extended them, they apparently found no need to apply a term. Rather, the term emerged when others outside the black freedom movements—particularly, the race- and ethnic-specific women's liberation movements, such as Black feminism—began to adopt the practice in the late 1960s. Traces of identity politics can also be found in the early writings of the modern gay liberation movements, such as Dennis Altman's Homosexual: Liberation/Oppression, Jeffrey Week's Coming Out: Homosexual Politics in Britain from the Nineteenth Century to the Present, and Ken Plummer's The Making of the Modern Homosexual.
One of the older written examples of it can be found in the Combahee River Collective Statement of April 1977, subsequently reprinted in a number of anthologies,and Barbara Smith and the Combahee River Collective have been credited with coining the term; which they defined as "a politics that grew out of our objective material experiences as Black women.
https://en.wikipedia.org/wiki/Identity_politics#History
So the term "identity politics" was coined by leftists - black militants, feminists, and gay rights campaigners. 
