Oh yeah, there is definitely an element of truth to it.
But I suspect on general demographic terms, "Hollywood liberals" and the like are closer to "everybody fucking else" in the general area, and, indeed, a good 25% of the American population who identify themselves as liberal in their voting habits, and not some sort of weird parastic evil agency/Illuminati controlling the media to keep Real Amurricans down through their sinister minority control of the airwaves.