Why do liberal whites hate themselves so much? Liberalism really is a mental disorder.
The neo-Marxists who emerged from the Frankfurt school in the 1940s (Marcuse, Adorno, Habermas), and their Marxist successors of the 1950s and 1960s (Foucault, Deleuze, Derrida) preached a "deconstructive" theory of society in which every interaction became cast as a power play between a perpetrator and a victim. This created a hierarchy of victimhood, with the white male as the universal perpetrator of injustice.
This was the only philosophy taught in colleges and universities beginning in the late 1960s, and came to be viewed uncritically by generations of students.
This philosophy became commonplace in the academia, media, entertainment, publishing, corporations, and has pervaded all spheres of political life in the West, but most sharply, in America.