The unfortunate part about many works of political thought, particularly I think from German philosophy is that you need to have a significant amount of prerequisite knowledge, and this has been my case with the Frankfurt School in particular. I simply haven't had the time to do the background reading, so the texts are a little mystifying to me. Take for example
The Dialectic of Enlightenment which is so very packed and dense that it reads like poetry to me, and what was accomplished in the first 20 pages therein could have been accomplished in a whole book by any authors other than Adorno and Horkheimer.
I have similar trouble with Society of the Spectacle, though I managed to find help getting through it. Some are more approachable though, like Marcuse's shorter essays, Marx's non-Capital economic works and Erich Fromm's Escape from Freedom. Edit: and of course Slavoj Zizek, though he is known to simplify and reduce concepts until the reader only gets a "kinda yeah" idea of what's being talked about.
Sometimes I really do wonder if the wealth of distracting information presented to me, so easy to grab in a capitalist economy has dulled my brain, or if I even had that brain to use in the first place.