It is easy to find quotes from prominent journalists and academics who claim that there is no systematic bias among media outlets in the U.S. . . .Although we expected to find that most media lean left, we were astounded by the degree. A norm among journalists is to present both sides of the issue. Consequently, while we expected members of Congress to cite primarily think tanks that are on the same side of the ideological spectrum as they are, we expected journalists to practice a much more balanced citation practice, even if the journalist's own ideology opposed the think tanks that he or she is sometimes citing. This was not always the case. Most of the mainstream media outlets that we examined (ie all those besides Drudge Report and Fox News Special Report) were closer to the average Democrat in Congress than they were to the median member of the House.
Our results contrast strongly with the prior expectations of many others.
[Think Tank Citations as] A Measure of Media Bias