The four words that threaten disaster for the ACA say the subsidies shall be available to persons who purchase health insurance in an exchange “established by the state.” But 34 states have chosen not to establish exchanges.

So the IRS, which is charged with enforcing the ACA, has ridden to the rescue of Barack Obama’s pride and joy. Taking time off from writing regulations to restrict the political speech of Obama’s critics, the IRS has said, with its breezy indifference to legality, that subsidies shall also be dispensed to those who purchase insurance through federal exchanges the government has established in those 34 states. Pruitt is challenging the IRS in the U.S. District Court for the Eastern District of Oklahoma, and there are similar challenges in Indiana, Virginia and Washington, D.C.

The IRS says its “interpretation” — it actually is a revision — of the law is “consistent with,” and justified by, the “structure of” the ACA. The IRS means that without its rule, the ACA would be unworkable and that Congress could not have meant to allow this. The ACA’s legislative history, however, demonstrates that Congress clearly — and, one might say, with malice aforethought — wanted subsidies available only through state exchanges.

Some have suggested that the language limiting subsidies to state-run exchanges is a drafting error. Well.