With the media, the majority of the "foot soldiers" lean left, personally, while the businesses that ultimately call the shots lean right. Since the "foot soldiers" are the ones in front of the camera or with their names on the byline, they feel the need to hold their bias in check, and they often overcompensate by leaning right, or at least taking ridiculous swipes at liberal politicians in order to establish the journalist's "bipartisan" bona fides. Meanwhile, the corporate owners have a kind of anonymity that lets them exercise their biases freely. The net result is that the media winds up leaning a bit to the right, especially on economic and foreign policy issues, and taking a lot more cheap shots at liberal politicians than conservative ones.
For a time, Obama was sheltered from that, since the media foot soldiers could demonstrate their "lack of bias" by taking cheap shots at Clinton, instead. The formula was to act like shameless boosters of Obama, then preempt conservative charges of liberal bias by mercilessly savaging Clinton for every imagined misstep. Now that Clinton is out of the line of fire, though, they need to take those cheap shots at Obama to combat charges of bias.
Many months ago I speculated about what would happen when the "irresistable force" of the media's crush on Obama hit the "immovable object" of the media's long-standing infatuation with McCain. At this point, it looks like the irresistable force is on the losing end.