John Hart writes, in comments:
Grasping Reality with Both Hands: The Semi-Daily Journal Economist Brad DeLong: I've taken the press's fawning over the likes of early GWB & McCain to be a form of exercising power. If you just report the truth, which is (by definition, I suppose) self-evident in light of the facts, then what have you really done? You've just written down something obvious.
But if you elide McCain's inanities, and you pretend his policies are equal to Obama's, well, then, you've done something hard - you've put one over one the reading public, and used your journalistic power to aid & abet in the telling of a lie. I think there's a thrill for some journalists in that.
I think that also helps explain why so many articles have the "well, the knowing reader will be able to suss out the lies, but I (the journalist) will only do 'he said, she said' and avoid even the simplest of conclusions."
Don't journalists get extra points for being "counter-intuitive"? What could be more so than dressing a lie as the truth? Plus there's something breathtaking about someone who keeps lying to your face, and every now & again the journalist wants to be in on the lie, and be the one who gets to wink.
I think John Hart is on to something. I recall the Washington Post's Clay Chandler as somebody who made it very clear that he would, if he thought it would advance his career, mislead his readers.