Liberals are having plenty of fun at the Maryland study out now showing that Fox News viewers are especially misinformed about current events (here's the study summary, pdf). Fair enough, and this adds to what we konw about how information is transmitted and, to some extent, how Fox can affect information flows. That's good to know.
What I think we know a lot less about, however, is how the partisan press functions -- not just Fox News, but MSNBC talk shows, and radio talk, and partisan blogs. Specifically, how much autonomy do these partisan outlets have? What sort of constraints, on topics or opinions, do they have? How do those constraints operate? I know we've had a couple of flaps recently about leaked internal Fox News memos about how to word certain things, and that those dictates corresponded with GOP talking points...how common is that? How top-down is it?
My guess is that most constraints are real, but not especially heavy-handed or, in most cases, top-down. They work the way a lot of things work in our party system: through networks, and through informal pressure and influence. In other words, Rachel Maddow starts talking about filibuster reform because the liberal guests she has on are all interested right now in filibuster reform, and activists in her audience are interested in filibuster reform -- not because the White House or the DNC or the Majority Leader's office told MSNBC to tell her to push filibuster reform. Although I should add: we do know that both parties do send out talking points, and presumably talk show hosts and their producers are reading them. More likely, Maddow has other very real, if informal, constraints; if she suddenly revealed she was secretly pro-life and began dedicating a segment every night to how Democrats should have more diversity of opinion on abortion, her credibility with her audience would disappear rapidly, and MSNBC would soon replace her with someone liberals could love and trust.
That also raises the point that there must be some sort of interaction between profit and partisan motivations for partisan media outlets. And then there are career incentives for individual writers, talk show hosts, and editors and producers.
But that's all speculation. I'm not even sure how someone would go about studying this, but if we're to have a partisan press -- and that seems pretty certain -- then we're gonna have to learn exactly what that means, and how it works.
(If anyone knows of good studies already done, please drop a comment! I'm aware that there have been studies like the Maryland one showing the effects of the partisan press, and also that there have been people who have documented the differences between what Fox and, say, CNN show, and that's all good too -- but I'm interested in something that's slightly different).