Republican leaders in the House and Senate have made clear that they’ll deploy every weapon in the legislative arsenal to repeal the Affordable Care Act. They’ll try to chip away at the taxes that support it and abolish the mandates that make its insurance markets work.

They might even stand on their heads and stop breathing if that would do the trick.

It’s a shame they are approaching matters this way. Various provisions of the Affordable Care Act have helped well over 100 million Americans, including about 20 million who gained coverage or got new insurance under the law.

In a rational republic, both parties might try to figure out how to improve the law. Why wreck it? But elections have consequences. So if Republicans invest a lot of energy in attempting to kill the thing — well, this is exactly what they told the voters they’d do.

It’s something else again if another part of the conservative power structure does a lot of the dirty work in undermining the law before Congress has to. I refer here to the hyper-activist conservative justices on our Supreme Court.

To the shock of many neutral legal analysts, four justices decided to take up an absurd legal challenge to the health-care law even before a lower court can rehear the case and before there is a conflict that typically triggers the high court’s involvement.

At issue is one phrase in the law that, in the worst possible construction, is a drafting error. It declares that subsidies to help people buy insurance will be available to those who were enrolled “through an exchange established by the State under [section] 1311.”

Conservative legal beagles, ignoring every other word in the statute, claim that the words “by the State” mean that any state that chose not to establish a health insurance exchange deprives its citizens of the federal subsidies they’re entitled to under the act. Since 37 states are expected to rely this year on the federal exchange envisioned by the law rather than establish their own, a ruling of this sort could deprive millions of their subsidies — and make a mess of the law.

Now let’s be clear: Not even the most conservative Supreme Court justices seemed to think this language was a problem before the conservative lawyers went to work.

In their dissent from the 2012 decision upholding the law, Justices Antonin Scalia, Anthony Kennedy, Clarence Thomas and Samuel Alito read the law exactly as its supporters do. They wrote: “Congress provided a backup scheme; if a State declines to participate in the operation of an exchange, the Federal Government will step in and operate an exchange in that State.” And they noted of the law’s structure: “That system of incentives collapses if the federal subsidies are invalidated.”

Five of the law’s lead architects, two senators and three House members, wrote Oct. 31 in The Post: “None of us contemplated that the bill as enacted could be misconstrued to limit financial help only to people in states opting to directly run health insurance marketplaces.” Conservatives are supposed to care about “original intent.” Well, here it is.

There’s another conservative legal school called “textualism,” which, as the name suggests, involves paying close attention to the actual text of a statute. Abbe Gluck, a Yale Law School professor, has written a very helpful article on SCOTUSblog that not only points to the straightforward reading of the law that the conservative justices offered in that earlier dissent but also cites none other than Justice Scalia to guide us as to what textualism demands.

Textual interpretation, Scalia insisted, should be “holistic” and “contextual,” not “wooden” or “literal.” Courts, he said, should adopt the interpretation of a law that “does least violence to the text,” declaring that “there can be no justification for needlessly rendering provisions in conflict if they can be interpreted harmoniously.”

If Scalia wants to be true to his own principles, can he possibly side with a convoluted reading of the law that apparently never occurred to him before?

Here’s a hypothetical for you: First, the Supreme Court issues a ruling that installs a conservative president. Then, he appoints two conservative Supreme Court justices who then join with three of their colleagues to make mincemeat of the greatest achievement of a progressive president elected by a clear majority. If such a thing happened in any other country, would we still call it a democratic republic?

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