Media critic Jay Rosen has a longish new post up synthesizing his thoughts on "the Actual Ideology of the American Press"--a topic his Twitter followers will recognize as a longstanding obsession. It merits reading in full, but the upshot is that--contra the narrative favored by partisans of both sides--the real and pervasive ideological bias of American journalists is not a simple reflection of the political commitments of either reporters or publishers, but an idiosyncratic bundle of professional norms that may, incidentally, cut in a conservative or liberal direction in particular cases.
I think this is, broadly speaking, pretty on point. I also note that Rosen is here steering us back from the now-common use of "ideology" to mean some consciously held system of explicit political beliefs and toward Marx's classic definition: "They do not know it, but they are doing it." Or as Slavoj Zizek, riffing on Don Rumsfeld, likes to say: Ideology is "the unknown knowns," the things you're not even consciously aware of believing.
Suppose Rosen is right that there is a distinct journalistic ideology--whether or not we think his description is accurate in all the details. (Better, I think, to say "ideologies"--beat reporters and Slate essayists, say, may each have their own hymnals.) One obvious question is where it comes from: What determines and sustains it? Parts, to be sure, are linked to the explicit canons of ethics they teach in J-school, but other parts don't seem to be. For Marx, ideology was determined by the dominant system of production--by which he meant that it was a kind of rationalization cooked up to protect the interests of those with economic power, comparable to the idea that press bias reflects the preferences of the owners and advertisers. But we can take it a little more literally and consider how the demands of selling and producing journalism might tend to reinforce some of the tendencies Rosen's talking about.