Only has happened once. In Ghostbusters, William Peck, a conceivably liberal EPA bureaucrat was cast in the "White male A-hole in a Suit" role.
Never again has any character conceivably liberal been cast as a villain in any Hollywood movie (can anyone think of one?)
I'm confused, probably because I'm not American, but what are the major personality differences between Lib and Dem? (I mean what distinguishing features or characterisations pigeon-hole William Peck as a Liberal)