Check out this article on bias, which goes through some very good arguments about why most of the whining about bias in the media is, well, biased:
"OK, let’s just get this over with: Yes, in the closing weeks of this election, John McCain and Sarah Palin are getting hosed in the press, and at Politico.
And, yes, based on a combined 35 years in the news business we’d take an educated guess — nothing so scientific as a Pew study — that Obama will win the votes of probably 80 percent or more of journalists covering the 2008 election. Most political journalists we know are centrists — instinctually skeptical of ideological zealotry — but with at least a mild liberal tilt to their thinking, particularly on social issues.
Before answering the question, indulge us in noting that the subject of ideological bias in the news media is a drag. The people who care about it typically come at the issue with scalding biases of their own. Any statement journalists make on the subject can and will be used against them. So the incentive is to make bland and guarded statements. Even honest ones, meanwhile, will tend to strike partisans as evasive or self-delusional.
Indeed, partisan politicos will consistently accuse any news source of being biased which does not agree with them, it is really that simple. They have their own expectations of what the results should be, and when those don't appear, they assume there is an unfair bias, usually with no other evidence at all, and with no considerations of the realities of the situation, like this:
"There have been moments in the general election when the one-sidedness of our site — when nearly every story was some variation on how poorly McCain was doing or how well Barack Obama was faring — has made us cringe.
As it happens, McCain’s campaign is going quite poorly and Obama’s is going well. Imposing artificial balance on this reality would be a bias of its own."
This is the point those who scream bias all the time never get. It's the exact same mentality that thinks it's biased to give evolution all the time in science class instead of splitting it with creationism. There may be two sides to every story, but that doesn't mean the truth is always midway between them. Sometimes the truth is far to one side, such as the fact that Sarah Palin gets picked on more than Joe Biden for her gaffes because her errors are more more egregious, and reveal far more ignorance of, well, everything, than his do. It is not a bias that Texas will get far more players on the Big-12 All Conference football team than will Baylor. That's the reality.
As for real bias, take the one Ron Paul mentioned on the news the other night: the bias the major parties give themselves in the way of major roadblocks for third parties. In a system where we are supposed to be able to have the freedom to challenge the status quo by running against it, third parties often have to spend much of their time and resources getting things that the two major parties get by default: a place on the ballot, and a seat at the debates. Oh, and then there is that little matter of plurality voting by state, and the all-or-nothing electoral system. Now THAT is a bias, making it virtually impossible for a third party candidate to win. Now I wonder why Republican and Democratic pundits never complain about that? There's your bias.