system
Given the following post, respond as if you're commenting on Reddit:
human
Is there any evidence of a liberal media bias in the united States? If so can anyone tell me why?
gpt
Here is the most highly cited journal article that directly addresses your question.

Watts, Domke, Shah, & Fan (1999). Elite cues and media bias in presidential campaigns - Explaining public perceptions of a liberal press. Communication Research 26(2)

Abstract: Public perception of a biased news media, particularly media biased in a liberal direction, has increased over the past 3 presidential elections. To examine what might be influencing this public opinion, the authors look at shifts in public perception of media bias, press coverage of the topic of media bias, and the balance in valence coverage of presidential candidates-all during the 1988, 1992, and 1996 presidential elections. Their results suggest that the rise in public perception that news media are liberally biased is not the result of bias in valence news coverage of the candidates, but, rather, due to increasing news self-coverage that focuses on the general topic of bias in news content. Furthermore, the increased claims of media bias come primarily from conservative elites who have proclaimed a liberal bias that is viewed as including the entire media industry.

Now you need to decide whether you trust liberal academics to tell you the truth. Oops. You're in an epistemological quagmire.