"Abandon all hope, ye who enter..." -Welcome sign above the City of Dis. "Kaos is my son."- Ravager

Pew Research Poll, with a handy dandy graphic.



So this is the overall sample.

Now let's see how informed and balanced the Fox Viewers are...



Now, this is a perception survey. What would a study require to be ideological? Why, a panel of trained coders (usually 2 or 3) that would rate ideological bias in a random sample of stories/covereage from each of the networks... which still comes down to perception, but trained perception.