The best description I've read of bias in the entertainment media and what it means from Andrew Klavan at Libertas:
All the same, it’s a relief to see it. I mean, personally, I would prefer my romantic comedy to come without partisan politics at all, but I suspect that’s almost impossible nowadays. One side has so much control over the narrative assumptions that underlie most movies that merely to work under a different set of assumptions is to declare an opposing position. I mean, in movies, the big corporation is always bad, the environmentalist always good; the gun-lover is always crazy, the religious guy always repressed or insane. The patriot is always a jingoist, wise men are always black, gays are always friends and advisors and, if you watch carefully, a poor man’s crimes are almost always traceable back to a rich man’s perfidy. The suburbs are always either comic or stifling, abortion may be rejected but never for moral reasons and – my personal favorite – the United Nations is always a force for truth and justice instead of the loathsomely corrupt gang of child-molesting, sex-trading kleptocratic tyrants we know and abhor.In short, at the movies, as on the network news, one worldview is assumed to be the steady state of affairs, while any other is considered a more or less ugly aberration. As a result, even the slightest indication that the hero of a movie might be, say, a Charlton Heston fan is bracing, a noticeable statement nearly shocking in its aggression. As for patriotism, faith, energetic capitalism – what some of us call normal on a good day – these become ferocious political pronouncements measured against a radical baseline.
Amen, brother Andrew. OK, I teased you, because to learn what it means you have to go visit and read the end. I will add a filip of my own - it's worse than described because the entertainment media and the news media provide a seemless web of reinforcing bias since they have the same ones.