They embarked on a mission to deconstruct or tear down major foundations of Western society (loyalty to the family, to religion, to the country etc.). For them, it was the ideology that counted, not the data.
In relation to Jewishness it's remarkable, since the School taught to reject your family (so you'd be less likely to be anti-Jewish), but they never supported Jewish children do the same. The Authoritarian Personality held out radical individuals as a cultural ideal; a prescription that Jews have never adopted. Instead they tend to have a strong sense of identification with the group.
Their work spawned a shitload of books, many funded by the AJC or the ADL, and all with the general idea that minorities should be tolerated by the majority, and the majority should not be concerned about their own eclipse. Any concern displayed by a member of the majority of becoming minority was viewed as a psychopathology.
Piece by piece the majority is dismantled: a White man can become gay and thus a minority and he will be of higher value, a White woman can become feminist and likewise.
A majority cannot exist, and if it does - in the thinking of the Frankfurt School and Boasian Anthropology - it is simply not dismantled yet (compare with Israel which demands a strong Jewish majority)