What is "critical social justice"? Is it the opposite of uncritical social justice? To be honest, it reads like the two spooky terms "race critical" and "social justice" conjoined in some word soup that's supposed to be very scary to people who are easily scared by ideas they don't understand.

Race critical social justice is not an ideology and more than set theory (yes, the math one) is. It's a way to view the world that provides you with certain insights. You don't need to believe in any particular solution to those problems in order to identify and examine them.