Actually, I don't think the liberal advantage is as great as it appears because of the quality and content of the respective audiences. Readers of the WashTimes and listeners to Rush are almost all committed conservatives. I also betcha Fox News is stoked with conservative refugees from CNN and the Big Three networks. Research shows the talk radio audience is better educated and wealthier - and they vote.
In contrast, many people watch the Big Three or take a major newspaper out of inertia or to get sports scores or because no alternative is available. I personally take two liberal papers, the Denver Post and NY Times because they give me a good overview of what's happening locally and in the world. I read them like people in the old Soviet Union read Pravda, knowing it's biased and filtering for bias as I read.
Bottom line is a definite minority of Big Three or even CNN watchers are committed liberal voters, where in contrast all but a tiny minority of Rush listeners are "broken glass Republicans."
The Dims are right to be worried. If they can't get people to vote for them with their present advantages, how will they do it as more media outlets follow the lead of Fox News to grow their audiences???
I heard a Russian born immigrant say that the American media is worse than the Pravda and more effective. He said it was because Russians knew that the Pravda was full of lies. Whereas the NYT and the like do not tell the readers, knowing and unknowing alike, that they are biased. They pretend to be main stream. Thus, the average reader does not question the headlines and articles.