Conservatives are dismayed about the Supreme Court’s complicity in rewriting the Affordable Care Act — its ratification of the IRS’ disregard of the statute’s plain and purposeful language. But they have contributed to this outcome. Their decades of populist praise of judicial deference to the political branches has borne this sour fruit.

The court says the ACA’s stipulation that subsidies are to be administered by the IRS using exchanges “established by the state” should not be construed to mean what it says. Otherwise the law will not reach as far as it will if federal exchanges can administer subsidies in states that choose not to establish exchanges. The ACA’s legislative history, however, demonstrates that the subsidies were deliberately restricted to distribution through states’ exchanges in order to pressure the states into establishing their own exchanges.

The most durable damage from Thursday’s decision is not the perpetuation of the ACA, which can be undone by what created it — legislative action. The paramount injury is the court’s embrace of a duty to ratify and even facilitate lawless discretion exercised by administrative agencies and the executive branch generally.

The court’s decision flowed from many decisions by which the judiciary has written rules that favor the government in cases of statutory construction. The decision also resulted from Chief Justice John Roberts’ embrace of the doctrine that courts, owing vast deference to the purposes of the political branches, are obligated to do whatever is required to make a law efficient, regardless of how the law is written. What Roberts does by way of, to be polite, creative construing (Justice Antonin Scalia, dissenting, calls it “somersaults of statutory interpretation”) is legislating, not judging.

Roberts writes, almost laconically, that the ACA “contains more than a few examples of inartful drafting.” That is his artful way of treating “inartful” as a synonym for “inconvenient” or even “self-defeating.”

Rolling up the sleeves of his black robe and buckling down to the business of redrafting the ACA, Roberts invents a corollary to “Chevron deference.”

Named for a 1984 case, Chevron deference has become central to the way today’s regulatory state functions. It says that agencies charged with administering statutes are entitled to deference when they interpret ambiguous statutory language. While purporting to not apply Chevron, Roberts expands it to empower all of the executive branch to ignore or rewrite congressional language that is not at all ambiguous but is inconvenient for the smooth operation of something Congress created. Exercising judicial discretion in the name of deference, Roberts enlarges executive discretion. He does so by validating what the IRS did when it ignored the ACA’s text in order to disburse billions of dollars of subsidies through federal exchanges not established by the states.

Chevron deference does for executive agencies what the “rational basis” test, another judicial invention, does for legislative discretion.

Since the New Deal, courts have permitted almost any legislative infringement of economic liberty that can be said to have a “rational basis.” Applying this extremely permissive test, courts usually approve any purpose that a legislature asserts. Courts even concoct purposes that legislatures neglect to articulate. This fulfills the Roberts Doctrine that it is a judicial function to construe laws in ways that make them perform better, meaning more efficiently, than they would as written by Congress.

Thursday’s decision demonstrates how easily, indeed inevitably, judicial deference becomes judicial dereliction, with anticonstitutional consequences. We are, says William R. Maurer of the Institute for Justice, becoming “a country in which all the branches of government work in tandem to achieve policy outcomes, instead of checking one another to protect individual rights. Besides violating the separation of powers, this approach raises serious issues about whether litigants before the courts are receiving the process that is due to them under the Constitution.”

The Roberts Doctrine facilitates what has been for a century progressivism’s central objective, the overthrow of the Constitution’s architecture. The separation of powers impedes progressivism by preventing government from wielding uninhibited power. Such power would result if its branches behaved as partners in harness rather than as wary, balancing rivals maintaining constitutional equipoise.

Roberts says “we must respect the role of the legislature” but “a fair reading of legislation demands a fair understanding of the legislative plan.” However, he goes beyond “understanding” the plan; he adopts a legislator’s role in order to rescue the legislature’s plan from the consequences of the legislature’s dubious decisions. By blurring, to the point of erasure, constitutional boundaries, he damages all institutions, not least his court.

© 2015, Washington Post Writers Group