I can see that interpretation as well, or it could be read as the libs stand for open-mindedness, diversity, etc., and yet they're the most narrow-minded people in the movie, and the Rush character is supposed to be the most narrow-minded of all, but he's not quite the firebreather they thought he was going to be. I don't know what political affiliation the filmmakers are, but if they are liberal, they failed miserably at making a movie to espouse their point of view!