There are lots of ways to view 'bias', and these do not necessarily come about because of any political agenda.
Cut and paste from the 'Rhetorica' website:
Is the news media biased toward liberals? Yes. Is the news media biased toward conservatives? Yes. These questions and answers are uninteresting because it is possible to find evidence--anecdotal and otherwise--to "prove" media bias of one stripe or another. Far more interesting and instructive is studying the inherent, or structural, biases of journalism as a professional practice--especially as mediated through television.
Commercial bias: The news media are money-making businesses. As such, they must deliver a good product to their customers to make a profit. The customers of the news media are advertisers. The most important product the news media delivers to its customers are readers or viewers. Good is defined in numbers of readers or viewers. The news media are biased toward conflict because conflict draws readers and viewers. Harmony is boring.
Temporal bias: The news media are biased toward the immediate. News is what's new and fresh. To be immediate and fresh, the news must be ever-changing even when there is little news to cover.
Visual bias: Television (and, increasingly, newspapers) is biased toward visual depictions of news. Television is nothing without pictures. Legitimate news that has no visual angle is likely to get little attention. Much of what is important in politics--policy--cannot be photographed.
Bad news bias: Good news is boring (and probably does not photograph well, either). This bias makes the world look like a more dangerous place than it really is. Plus, this bias makes politicians look far more crooked than they really are.
Narrative bias: The news media cover the news in terms of "stories" that must have a beginning, middle, and end--in other words, a plot. Much of what happens in our world, however, is ambiguous. The news media apply a narrative structure to ambiguous events suggesting that these events are easily understood and have clear cause-and-effect relationships. Good storytelling requires drama, and so this bias often leads journalists to add, or seek out, drama for the sake of drama. Controversy creates drama. Journalists often seek out the opinions of competing experts or officials in order to present conflict between two sides of an issue (referred to as the authority-disorder bias). Lastly, narrative bias leads many journalists to create, and then hang on to, master narratives--set story lines with set characters who act in set ways. Once a master narrative has been set, it is very difficult to get journalists to see that their narrative is simply one way, and not necessarily the correct or best way, of viewing people and events.
Status Quo bias: The news media believe "the system works." During the "fiasco in Florida," recall that the news media were compelled to remind us that the Constitution was safe, the process was working, and all would be well. The mainstream news media never questions the structure of the political system. The American way is the only way, politically and socially. In fact, the American way is news. The press spends vast amounts of time in unquestioning coverage of the process of government. This bias ensures that alternate points of view about how government might run and what government might do are effectively ignored.
Fairness bias: No, this is not an oxymoron. Ethical journalistic practice demands that reporters and editors be fair. In the news product this bias manifests as a contention between/among political actors (also see narrative bias above). Whenever one faction or politician does something or says something newsworthy, the press is compelled by this bias to get a reaction from an opposing camp. This creates the illusion that the game of politics is always contentious and never cooperative. This bias can also create situations in which one faction appears to be attacked by the press. For example, politician A announces some positive accomplishment followed by the press seeking a negative comment from politician B. The point is not to disparage politician A but to be fair to politician B. When politician A is a conservative, this practice appears to be liberal bias.
Expediency bias: Journalism is a competitive, deadline-driven profession. Reporters compete among themselves for prime space or air time. News organizations compete for market share and reader/viewer attention. And the 24-hour news cycle--driven by the immediacy of television and the internet--creates a situation in which the job of competing never comes to a rest. Add financial pressures to this mix--the general desire of media groups for profit margins that exceed what's "normal" in many other industries--and you create a bias toward information that can be obtained quickly, easily, and inexpensively. Need an expert/official quote (status quo bias) to balance (fairness bias) a story (narrative bias)? Who can you get on the phone fast? Who is always ready with a quote and always willing to speak (i.e. say what you need them to say to balance the story)? Who sent a press release recently? Much of deadline decision making comes down to gathering information that is readily available from sources that are well known.
