For most of this year, Mitt Romney’s strategy seemed to be working beautifully.

He spent much of the last several months laying low, if only to avoid being hit by shrapnel as each of his more wingnut-friendly opponents for the GOP presidential nomination imploded (hey, come to think of it, that would explain the helmet).  Michele Bachmann’s poll numbers rose and fell, followed by Rick Perry’s, then Herman Cain’s… and the only ominous note was that Romney’s own support seemed oddly unchanged through all the turbulence.

With the Iowa caucuses only a few weeks away, though, there’s not much time left for Newt Gingrich — the latest standard-bearer for tea-party Republicans’ tangled fantasies and resentments — to self-destruct.  So Mitt and his establishment GOP backers have finally come off the sidelines in hopes of doing the job themselves.

The anti-Newt ad by the Mittster’s shadow PAC, though, hints at the awkward challenges of appealing to the wingnut id.  Instead of simply recounting Gingrich’s history of shady ethics and power-craving arrogance, it leads with something that is presumably even more damaging — running against Newt will make Obama happy! The implicit message is that the teabag crowd detests President Obama as a person even more than they hate crooks and Washington, D.C., insiders… and I suppose it’s probably true.  The ad also dredges up Newt’s old global-warming spot with Nancy Pelosi — the visual evidence of consorting with the enemy being far more central to the ad’s theme than any supposed climate heresy.

At some point, the GOP nomination race will likely boil itself down to this festering core.  The ever-more-explicit McCarthyesque accusation will be, “Do you now or have you ever held a rational or cooperative belief?” And the ultimate winner’s answer will have to be, “No… every ounce of my body and soul is consumed by primitive tribal loyalties and hatreds!” Just ask Rick Perry, who’s trying hard to get there first.