It’s a matter of targeting, really. He’s not fighting Obama, he’s fighting the media.
More specifically, I think Mitt is attempting, and succeeding, in neutralizing the media’s influence on the election. For the most part, they are clearly perceived as Obama’s cheerleaders and water carriers.
The beautiful part is the harder the MSM works to divert attention from Obama’s failures, the more obvious their bias becomes. Thus, even if they achieve their tactical goal of temporarily directing attention away from whatever it is they are trying to hide, strategically, they are losing ground because their overall clout is further diminished.
If Mitt can “spike the guns” of the MSM, and force them to abandon their preferential treatment of Obama under the threat of losing all credibility, he’s won.
From that point, Obama will make enough mistakes to sink his own leaky boat.
I really like your analogy. This is how firemen fight fires: they cut off the source of fuel. Aim the water not at the flames themselves, but at their base.