A clarification...
Where I disagree with Tom is that I don't feel this is necessarily a conscious political program, or an ideological point of view.
I do not now, nor have I ever believed that the leftist bias of the media, or the Hollywood culture, is part of any organized system or targeted political agenda. It's more a case of "everybody I work with thinks these things." Believe me, it ain't easy to be a conservative and find work in Hollywood unless you were a really big name in the industry before your politics became known.