Well I think this argument would work except that you chose Fox News as your starting point. Yes the MSM all have agendas, however very few of them push it as hard a FN does theirs. Remeber, FN were the ones who went to court to protect their right to lie and not provide "news" but editorially biased content.
http://scholar.google.com/scholar_case?case=1262284675681492...