It all stared with modern theory being interested into the pedagogy . This was introduced by tge members if the Frankfurt school who left Berlin for elite universities all over the US and it spread from there. Basically, you deconstruct something down to having noy objective no objective morality, you can see what a sickness this has created. Al of the gender insanity comes from this. CRT is attempting to do the same with race. They can say: No one is teaching CRT classes, what they are doing is teaching teachers to teach all subjects through the lens of racism, just as they did with post-modernism decades ago, very successfully. Kevin Macdonald has some good commentary on this in his trilogy of books (check archive),