First off, I think everyone should go check out "Outfoxed" because it makes the point that all of the liberals are trying to make but haven't watched enough Fox News to accurately represent. Then also consider the survey that was posted above. That is the main problem. Not that this news station or that news station have certain politics. The problem is that people who consume certain outlets for their news have distorted views of reality. I agree that some liberal people are angered that Fox News exists because it has been a switch from the norm. However, I do not believe that makes their opinions totally worthless. Again, you guys need to check out "Outfoxed" to really have an informed debate here and not just bang heads.
http://www.outfoxed.org/
Also, that whole "Fox is popular and, thus, mainstream" argument...I don't know about that. It reminds me of Howard Stern's movie "Private Parts" where the radio guys are arguing about taking Howard off the air and one guy tells the other guy that Howard is listened to the most by people who hate him. I just think "popularity" as validation is misleading.