As the Supreme Court hears arguments about the constitutionality of the Obamacare individual mandate, Rick Santorum’s repeated emphasis that Mitt Romney is the Republican with the very least credibility to oppose Obama on health care might actually work to reinvigorate his campaign. For example, his repeat assertions became the basis for an obnoxious question from a notoriously obnoxious New York Times reporter. That obnoxious question in turn became the basis for a fundraising plea.

On a smaller scale, this little one-and-a-half-minute video drew snark from BuzzFeed’s Zeke Miller, who posted it under the headline, “Santorum’s Latest Attack on Romney: Massachusetts Residents Opposed to Obamacare.” He cheekily added the subhead, “His campaign found three.”

Miller’s subhead, though, suggests Massachusetts residents who disapprove of Romneycare are few and far between. But is that true? According to one mid-February poll, it is true that a vast majority — 62 percent — of Massachusetts residents have a favorable opinion of the law. Still, a third of Massachusetts residents disapprove of it. Unanimity on such a thing is virtually impossible — but 33 percent of Massachusetts residents amounts to more than just “three.” The plucky protagonists in Santorum’s video just happen to be the few the campaign caught on camera. Even the video provides more evidence than Miller gives it credit for, though: The three spokespeople are clearly at a gathering to oppose Obamacare/Romneycare — and they’re not the only three at the rally.

As long as we’re talking about what Massachusetts folk think of Romneycare, though, let’s consider a few other statistics from the same poll. A majority of Massachusetts residents — 54 percent — think Romneycare was a “major influence” on the national health care law, which is not as popular with the American public as Romneycare is with Massachusetts residents. Perhaps most importantly of all, nearly 70 percent of Bay Staters think Mitt Romney disagrees with the national overhaul because “he’s trying to win votes.”

This video and Rick Santorum’s relentless rhetoric about Obamacare/Romneycare and freedom are like stop signs on the campaign, urging voters to look in all directions before they barrel ahead with a Romney candidacy. It might be too late for Rick Santorum to win the majority of delegates before Tampa, but it’s not too late for him to stop Romney and he figures Obamacare/Romneycare is the way to do that.

Again, he might be right. At the end of a long primary, I can think of just a few reasons why Republicans have seemingly settled on Mitt Romney to take on a president whose greatest vulnerability, arguably, is the health care overhaul constructed atop the foundation Romney himself provided:

1. Republicans are simply most familiar with Romney (i.e. he has the highest name recognition of the remaining candidates). He’s been running for president for more than four years now, after all. Plus, he boasts excellent campaign organization and flush coffers that enable him to broadcast his message to a wide audience.
2. They don’t anticipate that Obamacare will be much of an issue in the general election even though it was an important issue in the 2010 election. They think the nation has Obamacare fatigue or they think the Supreme Court will rule the individual mandate to be unconstitutional and so take at least part of the issue off the table or they think it’s adequate that Romney has promised to work toward repeal. Whatever the reason, they think Obamacare has lost its potency as the prime example of the clash of progressive and free market forces in this country. They no longer see it as the president’s greatest vulnerability.
3. They actually think Romney can do a better job attacking Obamacare with the albatross of Romneycare around his neck than the other candidates could do without such an albatross.

As Jim DeMint recently said of Romney, “there’s a lot to like there.” His plan to reform entitlements, for example, is a marked improvement from the nonexistent plan the president has offered. His tax reform ideas are refreshing when compared with the president’s grating class-envy rhetoric. His personal presentation, while often criticized as robotic, has an indefinable presidential air about it.

But, when it comes to Obamacare, Rick Santorum is right: Romney has very little credibility with which to reopen the discussion of the president’s abomination of a health care law. If he’s the nominee and if he never does more than say he never wanted Romneycare to go national (i.e. if he never outright disavows the law), the GOP will have to tiptoe around the issue and the president will continually cast Romney’s health care lot with his, hoping to depress voter turnout among those who hate Obamacare and energize voter turnout among those who love it.