This is a question my brother is addressing in a paper he is writing a school paper about. He's trying to argue that the media is free market but has considerable restraints imposed upon it where gov't ultimately does have control over it. But at the same time the media has to have content that appeals to the public (which seems considerably pro state) so they can sell advertisement for revenue.
My brother has actually told me he's having a hard time finding "unbiasd" sources on "bias" media (imagine that

)eg they either demonize liberal or conservative media. Any suggestions for him would be welcomed.