Before the Supreme Court granted King v. Burwell, the Journal on Health Politics, Policy and Law invited me to write a counterpoint to an essay by Jonathan Adler and Michael Cannon, two of the architects of the litigation. I’m pleased to report that drafts of their point and my counterpoint are now available.

Writing the counterpoint allowed me to pull together a punchy, non-technical, and thorough explanation for why I think the challengers should lose this case. It also gave me a chance to emphasize the strongest argument in the government’s favor—a point that’s at risk of getting lost in the fog of statutory analysis.

To prevail, it’s not enough for the King challengers to show that it’s possible to read the ACA to eliminate tax credits from states that refused to set up their own exchanges. They must also demonstrate that the ACA does so unambiguously—and that the IRS’s contrary interpretation is therefore unreasonable. Under Chevron, if the ACA could be read in a couple of different ways, the courts owe deference to the IRS’s authoritative decision about how best to read it.

The challengers must therefore believe that the judges and commentators who read the statute differently than they do—including yours truly—are all behaving unreasonably. That’s an extraordinary claim, one that, as Adrian Vermeule has noted, “verges on self-refutation.” As I explain in my counterpoint:

[E]ven if you think that Adler and Cannon’s [interpretation] is plausible, maybe even attractive, the contrary interpretation offered by the government is at least reasonable. That brings me to the aspect of their argument that troubles me the most: their unyielding conviction that they’ve identified the only possible construction of the ACA. Nowhere do they so much as acknowledge the possibility that maybe, just maybe, they’re wrong.

That’s because they can’t admit to doubt. Because of the deference extended to agency interpretation, doubt means they lose. But their unwillingness even to acknowledge ambiguity reflects an important difference between legal advocacy and neutral interpretation. To be clear, Adler and Cannon deserve immense credit for their lawyerly ingenuity: they’ve constructed a facially plausible argument in support of an exceedingly strange interpretation of the ACA. But the courts would violate their obligation of fidelity in statutory construction if they mistook that ingenuity for genuine obeisance to congressional will. The latest challenge to the ACA is political activism masquerading as statutory restraint.