Some Republicans knew that nominating a governor who had signed a healthcare reform law with an individual insurance mandate would be a problem. It would muddy their anti-Obamacare message, they warned, even if Mitt Romney could claim that he supports mandates only at the state level. Well, their fears were well-founded.

Consider the gaffe made by Eric Fehrnstrom, a top Romney campaign adviser, on MSNBC Monday morning. As I reported on Sunday night, Republicans and conservatives have tried to make the best of the Supreme Court’s decision to uphold the Affordable Care Act by saying that if it is justified under Congress’s taxing power, then it must be a tax increase, and a massive one at that.

But Romney, who signed a law that, just like the ACA, imposes a penalty on individuals who don’t buy insurance, does not like to admit that he raised taxes. (That’s why, as governor of Massachusetts, he mostly sought to increase revenue through new and higher user fees, including preposterously cruel ones, such as imposing a $10 fee for a certificate of blindness.)

These conflicting lines got crossed when Ferhnstrom said, “The governor disagreed with the ruling of the Court, he agreed with the dissent that was written by Justice Scalia, that very clearly said that the mandate was not a tax. The governor believes what we put in place in Massachusetts was a penalty and he disagrees with the Court’s ruling that the mandate was a tax.” This flies in the face of claims by Congressional Republicans and conservative talking heads such as Rush Limbaugh, who say that the ACA is a tax. Fehrnstrom is also contradicting his own candidate who admitted back in 2008 that the penalty for not buying insurance in Massachusetts is a kind of tax.

But Congressional Republican aides tell the Washington Post’s Greg Sargent that they can continue to make this argument even as the Romney campaign says the opposite. He writes:

You’d think the fact that the GOP presidential nominee’s campaign has now confirmed that Obamacare’s mandate is not a tax would undercut the use of this talking point by GOP Congressional officials, right?

You’d be wrong. One senior Congressional aide tells me that Republicans will continue to describe it in those terms. And a second senior GOP Congressional aide emails that there is no contradiction here.…

The Romney campaign and Republican Congressional officials alike both agree with Scalia’s argument that the mandate is not a tax in the sense that claiming it is a tax makes it Constitutional, even as Republican officials continue to argue that the mandate is a tax in the sense that SCOTUS said it was in the course of upholding the law.

It’s a clever argument, and a sort of technically consistent. But, as Sargent’s Post colleague Rachel Weiner points out, “That line of attack is more easily maintained by Republicans who never imposed any such mandate.” It’s irritating to see the GOP paying so little political penalty for their complete flip-flop on the individual mandate, but it’s satisfying to see that by nominating Romney they will at least tie themselves into knots over it.