Where is the media middle?

John Douthat wrote a column in the New York Times a few days ago asking the question, "Can CNN be saved?" He basically contends that CNN's decision in 2004 to pull contentious shows like "Crossfire" in favor of more middle-of-the-road news programming has killed them in the everyday ratings. Douthat wants CNN to be more like John Stewart on "The Daily Show" and have more "lengthy, respectful and often riveting" debates.

But the research out there on selective exposure makes me wonder if Douthat's strategy would save CNN. Dr. Diana Mutz of the University of Pennsylvania noted in a paper for the Brookings Institute that "selective exposure is alive and well" with Republicans choosing Fox News and Democrats choosing NPR. Mutz goes on to argue that this selective exposure polarizes the electorate because those in the middle become disenchanted with politics and are less likely to participate. So this leads me to ask: If the middle is shrinking and that's where CNN sits, will there be anyone to even watch CNN's new "riveting" programming?