Horkheimer produced a long study after WWII, in which he combined Marxian theory with Freud to find ways to describe and measure antidemocratic, authoritarian tendencies. He called this the F Scale. There were 9 psychological variables:
This was very much a psychological critique. Horkheimer saw this as a developmental issue. Children who were raised under rigid discipline were likely to feel helpless and inferior, and project their hostility onto outside groups. Horkheimer thought that re-education was necessary.
Note that this psychological account is a kind of rationalization, and likely brings some comfort to people who are able to use it on those they disagree with.
By the way, note the irony in the use of the F-scale - it seems to incorporate the kind of positivism that elsewhere critical theory wants to disavow.