A theory of changes in media bias

So people watch the media that fits their views. But the intensity that different groups of people follow the news will vary systematically over time, just as there are midterm elections that tend to go against the party in power. From Politico:

The Pew Research Center for the People and the Press delivers data that puts last week’s huge election night ratings win for Fox News into some context:

While Republicans followed campaign news more closely than Democrats throughout much of 2010, partisans tracked the outcome at similar levels. Fully 57 percent of Republicans and 50 percent of Democrats say they followed the election results very closely. Roughly four-in-ten independents (41 percent) say the same. However, Republicans (61 percent) are more likely than Democrats (42 percent) and independents (39 percent) to say the election is the story they followed most closely.
Four years ago, when Democrats tallied large gains, Democrats tracked the midterm results more closely than Republicans or independents. At that time, nearly six-in-ten Democrats (58 percent) said they followed news about the election outcome very closely, compared with 47 percent of Republicans and 34 percent of independents.