In 1937, Horkheimer wrote about what is today known as “Critical Theory”.
Critical theory is a social theory which is about criticizing the way a culture and “society as a whole” function, in order to change it.
Contrast this with other social theories, which are more just about understanding and interpreting why things are as they are.
https://plato.stanford.edu/entries/critical-theory/
Herbert Marcuse uses "critical theory" to push an agenda.
He said that niggers,fags,feminists and other sorts of degenerates would lead the charge for change and is called "the father of the new left"
Marcuse's search for a form radical subjectivity that could serve as an impetus for revolution or social transformation led him down a path not traveled by his Frankfurt School colleagues. Indeed, one of the criticisms of Marcuse is that he gave in to pessimism and gave up on the working class as revolutionary subject. For Marcuse, we must look to “the substratum of the outcasts and outsiders, etc,” for any social change (MacIntyre 1970: 87).
https://plato.stanford.edu/entries/marcuse/