WHY ARE THERE SO MANY LIBERAL DOCUMENTARIES, and so few conservative or libertarian ones? That's a question asked in this article from the Washington Post.
One reason, of course, is lack of infrastructure -- film festivals, distributors, and powers-that-be in general tend to give films that take the "wrong" stance a chilly reception. I don't expect to see Michael Wilson at Sundance, for example.
But the article does ask: "why couldn't there be, for example, a documentary about the rise of political correctness on American campuses? "
UPDATE: Larry Ribstein thinks that the market for documentaries is inherently left-leaning. I'm not so sure about that.