For a great commentary on Shafer's piece, check out Andrew Cline's Rhetorica. I'll only add that, as a conservative (and one who was a liberal Democrat until about 1995), I still strongly believe that most reporting on crucial social issues comes from a left-of-center point of view. (Coverage of political races is fairly balanced, I believe.) Nowhere is this more true than in coverage of racial issues, as detailed in William McGowan's Coloring The News.
For more, check out old-time liberal Jim Sleeper's excellent Liberal Racism. Sleeper, by the way, had one of the more memorable lines about the media's soft coverage of racial issues. In a review of McGowan's Coloring the News, Sleeper wrote:
This country's vast race industry of activists, consultants, foundation officers, civil rights lawyers and government monitors enhances its funding, job lines and moral cachet by playing up bad racial news and discounting the good. ... (J)ournalists should be investigating the race industry, not working for it.
Amen to that.