There was, last week, a brief but thrilling moment in the GOP presidential contest: It seemed like, for the first time, a candidate would be attacked for being, not too liberal, but too far right. Back in the day, that wouldn’t have been too unusual, as when George H.W. Bush, in a remark that would haunt the rest of his career, mocked Ronald Reagan’s supply-side convictions as “voodoo economics.” This year though, in a fight universally described as among the nastiest in recent history, all the attacks have been in just one direction: from the right.

This has obviously been the thrust of the endless criticisms of Mitt Romney, who has evolved from 2008’s movement conservative champion to 2012’s Republican in Name Only—even as his own policy positions have become increasingly conservative. But Romney has recently used the same tactics against his current rival, Rick Santorum. With Santorum roaming across the land like a firebug, suggesting that American liberty itself could not survive another Obama term, did Romney or his surrogates go after him for conservative extremism? Of course not: Santorum was blasted to hell and back for being a fiscal liberal or even for being in the “liberal wing of the Republican Party.” Suddenly his much-regretted endorsement of his Senate colleague Arlen Specter became a Mark of the Beast that obliterated his many years of service to the conservative cause; his votes (along with most other Senate Republicans) for George W. Bush’s No Child Left Behind and Medicare Prescription Drug Benefit—understood at the time as central to Karl Rove’s master plan for building a conservative majority in the electorate—proved he was just another RINO.

This is the same pattern we’ve seen throughout the election: far-right politicians attacked for their lefty positions. When it became time for Team Romney to take down Rick Perry a peg or two, it didn’t go after the Texan for flirting with secession. No: The successful assault on Perry was all about his unconscionable sympathy for the children of undocumented workers. Similarly, Newt Gingrich never drew a bit of fire for his constant anti-Muslim demagoguery or his attacks on the moral fiber of food stamp beneficiaries. He first got into trouble for daring to question the political viability of Paul Ryan’s draconian budget proposals. Later on, Romney and Ron Paul led a joint attack on Newt for once expressing a belief in global climate change (and worse yet, appearing with Nancy Pelosi in an ad on the subject) and for allegedly criticizing Saint Ronald Reagan. When Gingrich rose from the dead yet again, he was definitively put down by Romney and his super PAC for the crime of receiving lobbying dollars from Freddie Mac, which, as every wingnut knows, conspired with ACORN and poor people to destroy the housing market and the financial system.

Even poor Herman Cain took flak for supporting TARP, and worse yet, for once serving on the board of a Federal Reserve Bank—the source, as Ron Paul taught, of all sorts of inflationary looting. And when Michele Bachmann was temporarily riding high back in the summer, none of her opponents took occasion to suggest she was a theocratic zealot who probably couldn’t carry five states in a general election. In the unwritten Code of 2012, it was simply impossible to be too conservative to be president.

Last week, though, it seemed like that dynamic might have finally changed. As Santorum’s attacks on the “false theology” of Obama and liberals gained press, sparking fresh attention to his past excommunications of liberal Protestants as outside the Christian fold, two opinion leaders on Team Romney opened a second front on the fiery Pennsylvanian. Matt Drudge put up lurid headlines and links about Santorum’s now-infamous 2008 Ave Maria University speech explaining American history as a “spiritual war” between God and Satan. And the designated conservative blogger at the Washington Post, Jennifer Rubin, called Santorum a “reactionary” for trying to attack the use of contraception instead of sticking to the safer culture war ground of abortion and same-sex marriage. Could it be that the “fiscal liberal” Rick Santorum was actually looking too conservative for the GOP?

Not for long. At Wednesday’s candidate debate in Arizona, Romney (again, with assists from Ron Paul) was back to attacking Santorum as a big spender and Washington insider, who couldn’t be trusted to decimate federal spending or savagely confront the hated partisan foe. And if Santorum manages to win in Arizona or Michigan, we’ll likely be hearing less from Team Romney about his “spiritual warfare,” and more about his alleged fidelity to the “liberal wing of the Republican Party”—which might be more properly described as an amputated limb.

Ed Kilgore is a special correspondent for The New Republic, a blogger for The Washington Monthly, and managing editor of The Democratic Strategist.