The stage is now set for a historic Supreme Court ruling on the constitutionality of the Affordable Care Act, a.k.a. health reform. Lower courts have split on whether Congress may require individuals to buy health insurance or pay a penalty; the Obama administration has skipped an opportunity for additional lower-court review and asked the Supremes for a definitive decision. We could have it by June – right in the middle of the presidential campaign.

Gosh, I hope not. No matter which way the court goes, its opinion – or, more likely, its split opinion – is bound to inflame and polarize an already badly inflamed and polarized electorate. The country and the court need that like a hole in the head.

At The New Republic, the estimable Timothy Noah says President Obama’s decision to seek prompt review is, for Obama, a political “win-win.” If the Court upholds the ACA, Tim reasons, “we will all be reminded that this sole accomplishment makes Obama the most consequential Democrat since Lyndon Johnson to occupy the Oval Office.” If the Court strikes it down, that “would be a fantastically effective way to ‘energize the [Democratic] base,’” because Obama could campaign against a right-wing court. 

What Tim leaves out is the effect of a Court ruling in favor of the law on the Republican base. Having tried and failed to strike it down in the courts, conservative voters will be that much more determined to elect a GOP House and Senate to repeal it legislatively, and a GOP president to sign the repeal bill.

Indeed, the conservative backlash against a pro-ACA ruling could well be stronger than a liberal backlash against an anti-ACA ruling. That’s because electing a Republican government offers conservatives an alternative means to get their desired policy outcome; but if the Court struck the law down, liberals would have no hope of re-enacting it whether Obama gets re-elected or not.

ACA’s supporters should not overestimate how many voters see it as “an accomplishment.” A CNN/Opinion Research poll in June found the public split 56 – 39 percent against the statute – consistent with the vast majority of polls since July of 2009. The least popular provision in the bill is the one before the Supreme Court: the individual mandate.

As I’ve argued elsewhere, the constitutional case against the individual mandate is stronger than supporters of the legislation acknowledge. Even so, this is a very close question, whose particular resolution by the Court could have a lot of unintended and unforeseeable consequences for other federal laws and the overall federal-state balance of power.

In short, it’s a legal can of worms better left unopened, or at least not opened unless absolutely unavoidable.

If they rule in June, the justices, five Republican appointees and four Democratic appointees who often split 5-4, would unavoidably be accused of trying to influence the presidential election – or, alternatively, of having been influenced by politics themselves. A mid-campaign decision is far more likely to fuel partisan rancor than help forge consensus. Everyone on the court could lose legitimacy – the four conservatives, the four liberals, and the perennial man in the middle, Justice Anthony M. Kennedy.

Fortunately, there is a way out: the court could dismiss the case for lack of jurisdiction, citing a federal statute that bars courts from considering challenges to taxes before they have actually been levied. For all the eagerness with which the law’s opponents have rushed into court to stop it, and for all the urgency with which the Obama administration now demands that the court uphold it, the individual mandate, and the accompanying financial penalty, does not take effect until 2014.

Surely this lawsuit can wait until there’s a plaintiff who’s actually been told to get insurance, or else. In the meantime, Congress could well repeal or change the law -- or at least the mandate -- thus rendering the whole constitutional dispute moot. Letting the political process run its course is what judicial restraint is supposed to be all about.

Yes, this might require the justices to rule that the penalty by which Congress decided to enforce the individual mandate is tantamount to a tax – and to do so in a way that would not foreclose their power ultimately to rule on the merits. A bit of a stretch. But a clever opinion by Judge Diana Gribbon Motz of the U.S. Court of Appeals for the 4th Circuit shows how it can be done.

Five years ago, the finest appellate lawyer of his generation stood before an audience of Georgetown University law students and explained that, for the Court, restraint is often the better part of valor: “If it is not necessary to decide more to a case,” Chief Justice John G. Roberts Jr. said, “then in my view it is necessary not to decide more to a case.” He and his colleagues need to remember those words, and live by them, now.