AS GOVERNOR of Massachusetts, Mitt Romney passed health-care legislation that mandated the purchase of a health-insurance policy, under the threat of a monetary penalty. That's how Obamacare works, too. Mr Romney's delicate federalist argument against Obamacare, perfected during the primaries, was that health-care reform ought to be state-based, that an individual mandate is perfectly acceptable at the state level, but at the national level represents an unconstitutional abuse of congressional regulatory power under the commerce clause. The Supreme Court said that the commerce clause needn't have anything to do with it. As long as the penalty aspect of the mandate is conceived as a tax, all is well, constitutionally. Following the Obamacare ruling, the Romney campaign predictably said that it does not see the penalty as a tax, and remains in its conviction that the mandate is unconstitutional on commerce-clause grounds. Signing on to John Roberts' reasoning in the decision would have implied that the court did not decide the case incorrectly, that Romneycare imposed a tax on uninsured Bay Staters, and that there is, after all, no principled distinction between Romneycare and Obamacare, as the federal government's tax powers aren't in dispute. So, as Brian Beutler of TPM writes:

It shouldn’t have taken Washington’s top Republican operatives more than a few minutes to recognize that attacking the mandate as a tax would put Mitt Romney in an even more uncomfortable position vis-a-vis the Affordable Care Act than he’s already in and, implicitly, give John Roberts and the Supreme Court a pass on the legal argument.

But, of course, attacking the mandate as a tax is exactly what movement conservatives have done. "[O]n the whole it would’ve made sense to defer to the Romney camp’s original view that the mandate is a penalty—not a tax—that the Court should have struck down", Mr Beutler rightly maintains. Unfortunately for Mr Romney, the Wall Street Journal editorial boardisn't in the business of making sense, and hammered their candidate for not getting with the programme.

Predictably, Mr Romney has awkwardly acquiesced. And, predictably, Mr Romney is now getting grief for having claimed he didn't hike taxes in Massachusetts. On the campaign trail, Mr Obama is sticking it to Mr Romney for spineless flip-floppery, predictably.

None of this is much helping Mr Romney. The mandate was unpopular as a penalty and isn't going to become much less popular as a tax. So what's going on? Why were Republicans so eager to push their man into a corner? Part of the problem is that, for all their swagger, movement conservatives are nervous about their ability to win big elections without running against tax increases. David Weigel writes:

Ideally, if you're a modern Republican presidential candidate, you get to run against a candidate who raised taxes. You can promise relief from those taxes. That's why, from a WSJ perspective, Romney so badly needs to frame the Obamacare penalty as a Middle Class Tax Hike. There's no other massive tax hike to run against!

A related but different problem for Mr Romney is that partisans are by nature Pavlovian, and simply can't help drooling when the bell is rung. Republicans heard the dinging of the word "tax" and thoughtlessly went on the attack. As Mr Beutler put it, GOP operatives "saw a shiny object chased after it, and ran roughshod over Romney along the way". And this isn't the only shiny object that has gotten Mr Romney trampled by his own party. Mr Beutler continues:

This seems to happen over and over again. The Obama campaign has been deft at keeping other major stories in the news—from student loans to women’s rights to tax equity to immigration and on and on. It’s all perfect bait for movement conservatives and House and Senate members, and each time they take it you can practically hear the cries of frustration from Boston.

Of course, if Mr Obama prevails in November, conservative true believers will pin the blame on Mr Romney both for failing stay "on message" about the economy and for failing to signal sufficiently conservative zeal on the issues his nominal allies are making it impossible for him to avoid.

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