In some ways Zappa was a lot less liberal than you'd think, he was all over the place and changed on several things as he got older. But as a boss he was a fascist against alcohol and drugs. By the early '80's he had a policy of firing anyone that got high or drank on or off the job! - per my friend, Zappa's comptroller for tours.
Interesting. I know he wasn't a hardcore lib, but his comment on marxism was on the money. I'm not surprised about the alochol policy, though, I've heard about that from a number of bands. It's okay when they're young and partying, but once schedules are getting messed up because someone ELSE is doing it, and now you're the boss, things change.