Everybody is speculating about what the impact on President Obama will be if the Supreme Court strikes down the health-care law. Understandable, since the law originated with him. But it got me wondering: what about the impact on the Romney campaign? I haven’t read a word about this, I suppose because it’s generally assumed that any crushing defeat for Obama (the conventional wisdom on an adverse high-court ruling) is a moment of ecstasy and mirth for Mitt Romney. But it isn’t necessarily so. A ruling against the law, depending on its scope, has three possible effects. It takes a massive campaign weapon out of his hands. It forces him to answer a key question he has so far not had to answer. And finally, and it has the potential to put him on the defensive since he will have to align himself with an obviously political and unaccountable Court majority.

On the simplest level, Romney’s campaign thus far is built around two bullet points. First, the economy. He wants a campaign that is chiefly about anemic job creation. Now, his problem is that the economy may well be humming along nicely by the fall, with several straight months of 200,000-plus private-sector jobs gains and an unemployment rate down around (or maybe below) the 7.9 percent that it was the day Obama took office. These facts would make Romney’s sale more difficult, certainly. But it’s his main calling card, and it fits tongue-in-groove (or so he says) with his own résumé, so it’s where he wants to keep the conversation.

And that second bullet point, his biggest applause line with conservatives for months? Repeal Obamacare. If the court’s ruling against the ACA is fairly narrow, and throws out only the mandate, he’ll still be able to talk about getting the bill off the books. But if the court rules more broadly and strikes down the whole law, then Obamacare will already have been repealed. This may seem analogous to the problem of having too many presents to open on Christmas Day, but it actually presents two challenges to the Romney campaign.

First: Millions of right-wingers who would have been more motivated to vote by their hatred of the health-care law still will be less likely to show up on Election Day. This will get picked up in Romney’s polls—two, three points—and he’ll have to do something to re-motivate these people, and that something might alienate swing voters.

Second, and more substantively: By the fall, I’m guessing, if the ACA is overturned, the media will be demanding of Romney that he explain how he’s going to make sure people with pre-existing conditions can get reliable coverage. He could not do that the other night to Jay Leno. In fact, while he obviously didn’t intend to, he ended up defending . . . the individual mandate! “You’ve got to get insurance when you’re well,” he said, “and if you get ill, then you’re going to be covered”—precisely the logic behind the mandate (which we all know he “secretly” accepts, which is why he supported it as Massachusetts governor).

If the Democrats are doing their job, voters—and perhaps especially independent voters—are going to realize by the fall: “Hey, wait a minute, we didn’t quite know repeal meant that people with pre-existing conditions wouldn’t get coverage.” To be sure, repeal may or may not mean that, depending on how broad it is. But if it does, then Romney will have to come up with some answers. And the problem is, there are no honest answers that don’t involve the government doing . . . something. Given the guy’s propensities toward pretzel logic in the first place, this may prove to be a challenge for him.

But the Court itself might be Romney’s biggest problem. Again, this will depend to some extent on the scope of the ruling, and even the tone of the majority opinion. But if either provides any fodder for the “Supreme Court is out of control” argument, that is a potential albatross around Romney’s neck.

“Potential” because this will depend, to a considerable extent, on how Democrats and liberals react to an adverse ruling. If (as is all too possible) a circular firing squad forms, and it’s all about recriminations and all the things the White House did badly in selling the ACA (and there are many), then Romney skates home. But if a negative ruling galvanizes the broad left and focuses its collective mind on cogent arguments that appeal to swing voters, then it’ll be Romney who will find himself on the defensive, because the left in that context can turn the Court into a major campaign issue.

Three-quarters of the public thinks politics will influence the Court’s decision. That figure included fully 80 percent of independents (interestingly and perhaps touchingly, just 65 percent of Democrats thought the Court would rule politically). So when a political ruling is handed down, the worst suspicions of four out of five independents will be confirmed. Let Romney praise Scalia and Alito to the heavens in that context.

Look, there’s no question that an anti-ACA ruling is worse for Obama, at least in the short term. But I can guarantee you that the Romney campaign is hoping for a narrow and modest ruling against the mandate that is as non-incendiary as possible—if not, indeed, hoping that the thing is upheld, so they can keep using it as a bludgeon. Anything else gives them headaches and makes them answer questions they’d rather see not asked.