Recently Leland Yee, an anti-gun, California state senator and candidate for Secretary of State was arrested on charges of gun-running involving Islamic extremist groups in the Philippians. While this story has received a lot of attention from right-wing media it has only gotten local coverage from the MSM. In fact, the only non-partisan, national publications to cover it have been Popular Science and Esquire. When asked, CNN explained that they don't carry stories about such figures as state senators because they are local. Glen Reynolds, the Instapundit, found numerous stories on their site about state legislators. He blames the lack of coverage on the fact that Yee is a Democrat and the press is providing cover for him on political grounds. While I agree that the press is burying the story, I disagree about the reason.
It is true that the press is overwhelmingly Democrat and this does color their coverage. Typically a Republican who is in trouble has his party affiliation announced in the headline or the first sentence. Democrats seldom have their party announced before the third paragraph if at all. But this is a change in emphasis.
I think that the real problem here is issue-advocacy. While most reporters know that they need to cover straight news regardless of party affiliation, most are willing to bend the rules over issues that they believe are in the public interest. In these cases, there is no pretense at balanced journalism. Anyone who watches 60 Minutes or watched the old tv-show, Lew Grant, has seen issue advocacy. The idea is to use he power of the press to change the world for the better. Journalists actually feel proud of this.
Since most journalists are liberal the issues they advance are liberal causes. This makes it hard for outsiders to distinguish between partisan behavior and issue advocacy.
Usually issue advocacy involves slanting a story but it can include suppressing a story. In this case, the issue is gun control. Yee had been a leader in anti-gun legislation so his arrest on federal weapons charges hurts his cause immensely. I think the fact that Yee is a Democrat is secondary to the various editors who passed on the story. They are more interested in the gun-control angle.