The myth often promoted by hard core conservatives that they or their views are not treated fairly by the supposedly liberal media. This notion comes from various surveys that show that a typical sampling of journalists are likely to be slightly more liberal than average.
However, using such surveys as proof overlooks the much harsher realities. First, all major media outlets are owned by large corporations that have pro-big business and low regulation preferences. Secondly, where news agencies were once considered a public service they are now seen as having to be self supporting through advertizing. And, advertizers tend to favor a pro-big business point of view. Third, Fox handpicked its staff to be conservative even more so than CNN. Fourth, radio is quite extreme in its conservative to liberal ratio. In 2004 Air America which was the biggest liberal radio network was only broadcast on 14 radio stations compared with 5,000 that carried Bill O'Reilly, Hannity, and Rush Limgaugh and another 4,000 that carried consevative religious programming. In fact, through most of its history MSNBC was conservative like CNN having such hosts as Ann Coulter and Tucker Carlson and Imus for its morning program. MSNBC has since become more liberal in primetime with Ed Schultz, Keith Olbermann, and Rachel Maddow but nevertheless retains a strongly conservative slant with Morning Joe.
The liberal media bias excuse when invoked is similar to justifications used by alcoholics to dismiss their addiction. It could also be viewed as an ad hominem attack to dismiss bad press in much the same fashion as dismissing the members of a particular race, religion, or heritage.
Tom Delay insists he was a victim of liberal media bias.