Namely, they assumed that the subsidies were available on the federal exchanges and went so far as to argue that the entire statute could not function as written without the subsidies. That’s a far cry from their argument now that the statute makes crystal clear that Congress intended to deny subsidies on the federal exchanges.The challengers are now saying that there couldn't possibly be any way to read the statute without concluding that the lawmakers writing it meant to say that anyone buying health insurance on the federal exchange—as opposed to those set up by a state—would not be eligible for a subsidy. Gluck points to this brief where the challengers included the subsidies within the exchanges integral to how the system would operate "as intended by Congress." And in their reply brief, they again show that they assume that the subsidies are critical to sustaining the exchanges. So, if it is so plainly clear in reading the statute now, in 2014, that subsidies weren't going to be available to everyone, why wasn't it in 2012 when these briefs were written, when the lawyers were obviously deep into the statutory language?
I am not a fan of the “gotcha” flavor that some aspects of this case have taken on, but the challengers’ 2012 statements are relevant as a legal matter because what the government has to prove to win—as a matter of black-letter law under the Chevron doctrine—is that the statute is ambiguous. (Chevron says that federal courts defer to the relevant agency’s reading of the statute when a federal statute is unclear—here, that agency is the IRS.)
Gluck goes further to show how the dissent by Justices Scalia, Kennedy, Thomas and Alito shows exactly the same understanding of the statute—that the subsidies are integral to the exchanges and the operation of the entire system. None of those judges picked up on what is supposedly so obvious in the law—that Congress didn't mean for people signing up on federal exchanges to get subsidies. The plaintiffs lawyers and the judges as well as the sympathetic justices—all of them—read the statute and did not come away from it believing what these same lawyers are arguing now. None raised the question of why Congress had purposely written the law to keep potentially millions of people from benefiting by it.
As Gluck concludes, "all the government needs to show under the law is that the statutory text is, at a minimum, ambiguous—that there are at least two ways it can be read." The law's challengers—and the conservative justices—proved that by giving one interpretation in 2012, and another in 2014.