Usually this happens on fiscal issues, where the mainstream press’s attitude for the last few years has often been: “We need a grand bargain and we don’t care what is in it!” And usually bipartisanthink irritates liberals more than conservatives, because liberals sense — accurately enough — that many of the media personalities talking up, say, the Simpson-Bowles deficit plan would actually be perfectly happy with President Obama’s deficit plan, but feel a professional obligation not to admit it. Conservatives, meanwhile, tend to be more frustrated by bipartisanthink’s cousin, “leading the conversation.” This is how the mainstream media tend to cover social issues, and it involves acting as a crusading vanguard while denying, often self-righteously, that anything of the sort is happening.

I’m borrowing the term from The Daily Beast’s Howard Kurtz, who used it to describe how the press (while also “being fair to all sides”) should handle the aftermath of the Newtown shootings. The trouble is that when you set out to “lead” a conversation, you often end up deciding where it goes, which side wins the arguments and even who gets to participate. This was clear enough in Kurtz’s own piece, which assumed that stricter gun control was the only rational policy response to Newtown. And it’s been clear enough in all of the culturally charged debates — over guns and gay marriage, immigration and abortion — that have attracted media attention of late.

On these issues, an official journalistic commitment to neutrality coexists with the obvious ideological thrust of a thousand specific editorial choices: what kinds of questions are asked of which politicians; which stories get wall-to-wall coverage and which ones end up buried; which side is portrayed as aggressors and which side as the aggrieved party, and on and on and on.