"Trench wafare"? Whose metaphor is this?

From HuffPost:
Shaken Clinton Camp Prepares For Trench Warfare After NH
Thomas B. Edsall

If someone from the Clinton campaign used this metaphor, it's a very bad sign. "Trench warfare" doesn't have a brilliant history: from the Union's siege of Petersburg during the Civil War, to the extended trench warfare of WWI, it leads to loss of morale, extended indecisive confrontations, and mass casualties. The generals of WWII used every device at their disposal to avoid trench warfare - tanks, in particular. Mobility, not static defenses, have dominated modern battlefields.

I suspect Edsall himself came up with the metaphor, to describe what sounds something like a strategy of attrition:

Looking to leverage Obama's slender resume, a Clinton operative argued to HuffPost that the campaign will be able to demonstrate that "Obama is just not a plausible person in this environment of international peril," and that the longer the primary campaign can be extended, the better chance Clinton will have to prove that "there is not even a second level to Obama, there is no depth."

I suppose it's not completely inaccurate to describe a strategy that relies on simply hanging on long enough "trench warfare", but I wouldn't have picked that term.

The article, however, does ask a pertinent question: "What can Hillary do?"

On the battlefield - to pursue the chosen metaphor - mobility is employed to attack the enemy - to position your forces to bring concentrated, coordinated firepower to bear on the enemy, allowing the enemy little time to respond. [Anzio is a great example of positional advantage achieved by mobility... only to be squandered by not exploiting the advantage, and allowing the enemy to regroup.] In the best of all possible worlds, simply having achieved a positional advantage is sufficient to secure the victory, without firing a shot.

Given that Clinton is correctly reluctant to attack Obama directly, maneuvering to achieve a favorable position may be the best she can hope for. Great. How?

"Rhetoric vs. Results, Talk vs. Action."
Pointing out Obama's lack of experience, and characterizing his appeal as brilliant rhetoric without demonstrated achievement seems not such a great idea. The problem is not that it's untrue, but that it invites voters to examine Clinton's actions... which include votes for Iraq AUMF and Kyl-Lieberman - the latter as recently as last summer! "Senator Clinton asks us to examine not her words, but her actions. Fine! Let's examine her actions..."

This particular parry is ready-to-hand, suggesting the offensive thrust will not be effective.

It's been fun trying to extend the military metaphor, but I think I'm now exhausted from all the fighting! Good night!