"The challenge [Romney] faces is unique: he is acting, and is being treated as, the incumbent rather than the insurgent."

Breitbart's Joel B. Pollak tries out a template:

The media have also treated Romney as the incumbent, pouncing on every word and gesture, seizing on every mistake and inventing errors where none exist. Romney’s so-called “gaffes” have one thing in common: they are all statements of fact. He is being held to a presidential standard--for presidents should know better than to tell all--while Obama’s outright lies to the nation (on Libya, the debt, etc.) are ignored by the media.

Let me offer an alternate template: The media have been treating Romney as the Republican, which he is, and Obama as the Democrat, which he is.