MY COLLEAGUE adheres to a theory about why the text of the Affordable Care Act, otherwise known as Obamacare, clearly authorises federal subsidies for health insurance purchased through exchanges set up by state governments, but not for insurance from exchanges set up by the federal government. This is the question at issue in King v Burwell, the Supreme Court case that could strike down Obamacare's subsidies in 34 states and force millions of Americans to lose their health insurance. The failure to explicitly authorise subsidies for health insurance from federal exchanges comes from a four-word phrase in the 900-page law, which refers to subsidies for insurance from exchanges "established by the state". The theory, advanced by the plaintiffs in the case, is that the authors of the law intended to use the threat of denial of subsidies to pressure states to set up their own exchanges. "It was, I think, very much part of the law's strategy to induce states to establish exchanges," my colleague writes. "Advocates of Obamacare now deny this, and understandably so. Otherwise, [Barack] Obama made a very risky bet and lost in a decisive and humiliating way." This is an interesting theory. If it were "part of the law's strategy" to use denial of subsidies as a threat to induce states to set up exchanges on their own, one assumes that the law's authors must have discussed this strategy at some point, at least amongst themselves. If we go looking for this evidence, what do we find?

There is no record of Barack Obama ever saying, in public or private, that states that did not set up their own exchanges would not receive subsidies. Everything Mr Obama has ever said about the law indicates that he believed that states with federally established exchanges would receive subsidies too. This is unsurprising, since his administration has been eagerly distributing those subsidies. One might hypothesise that Mr Obama once (secretly) planned to deny such subsidies, only to execute a (secret) turnaround at some point. A shred of evidence supports this notion. In two lectures in 2012, Jonathan Gruber, a health economist who had helped design the basic structure of the law, said that he thought that most states would be lured to set up their own exchanges because "if you're a state and you don’t set up an exchange, that means your citizens don't get their tax credits". This appears to be the only time anyone associated with crafting the law ever considered this idea. (Mr Gruber later said he must have slipped up and misunderstood how the law would work.)

In any case, the beliefs of Mr Obama and his administration are of marginal relevance, because they did not actually write the ACA. It was written by members of Congress and their staffs. So did limiting subsidies to state exchanges play a role in the drafting or discussion of the bill? Robert Pear of the New York Times recently investigated this question for us. The staff who wrote the act, and the Senators who considered it, say nothing of the sort happened.

“I don’t ever recall any distinction between federal and state exchanges in terms of the availability of subsidies,” said Olympia J. Snowe, a former Republican senator from Maine who helped write the Finance Committee version of the bill. “It was never part of our conversations at any point,” said Ms. Snowe, who voted against the final version of the Senate bill. “Why would we have wanted to deny people subsidies? It was not their fault if their state did not set up an exchange.” ...The idea of denying subsidies to people who bought insurance through the federal exchange “was never discussed,” said Charles M. Clapton, a lawyer who worked on both committees for Senator Michael B. Enzi, Republican of Wyoming. Mr. Clapton said he had difficulty accepting the argument advanced by the plaintiffs because it was “so contrary to the intent” of those who had written the legislation.

Mr Pear goes on to cite former Senator Jeff Bingaman, Democrat of New Mexico; Christopher Condeluci, then a staff lawyer for Republicans on the Senate Finance Committee; Russ Sullivan, the staff director for Democrats on the Finance Committee; and Robert Greenawalt, who worked as a senior tax adviser to Harry Reid, the Democratic Senator from Nevada who oversaw the merging of different bills into the Act's final language. All agree that the idea of denying subsidies to states that did not set up their own exchanges never came up.

“I remember meeting after meeting in which we went through the language of the legislation line by line,” said [Mr Greenawalt]. “I do not recall any discussion of a distinction between federal and state exchanges for the purpose of subsidies.”

The sources Mr Pear cites tell a familiar story, similar to that sketched in manyother articles. (It also matches the amicus brief filed by members of Congress and their staff, which my other colleague noted back in February.) The original text of the bill setting up the exchanges was written in the Senate's Health, Education, Labor and Pensions Committee. The text of the bill setting up the subsidies, which are distributed as tax credits, was written in the Senate's Finance Committee. The Finance Committee originally assumed all states would set up their own exchanges, and wrote the language for the subsidies on that basis. But they gradually realised that some states would not, and thus created a separate provision allowing the federal government to set up exchanges in those states. They failed to clearly specify that the tax subsidies would also be available in such states. In October 2009 the two bills, written by non-partisan professional drafters, were merged by senators and their aides. But they did not notice the omission in the original Finance Committee bill's language. The committee Mr Reid chaired did a rather slovenly job of merging the bills because major changes would have required taking it to conference committee with the House, which had in the interim gone Republican in the 2010 elections. That helped the peculiar drafting error stay in.

It is possible that neither Mr Pear's sources, nor the members of Congress and congressional staff who filed the amicus brief, were in on the real action. Maybe somewhere in the background Obama administration heavies were manipulating this chaotic process to preserve their four precious words and retain the incentive of denying subsidies in order to push states to set up their own exchanges. Yet it still seems a singularly inept strategy. If the ACA's authors had wanted to force states to set up exchanges themselves, they could have saved everyone a lot of effort by not authorising the federal government to set up exchanges at all. It is hard to understand why the bill's authors would have gone to the trouble of authorising federal exchanges if they intended to render them useless by denying them subsidies.

Still, a bigger problem looms over the entire theory. My colleague seems to be arguing that denying subsidies to non-participating states was a sort of bluff, a doomsday machine the Obama administration constructed in order to frighten states into setting up exchanges. But as Dr Strangelove so perceptively observed, "the whole point of a doomsday machine is lost if you keep it a secret!" The fact that no one in the Obama administration, none of the ACA's authors in Congress, none of the bill's advocates in civil society, none of the insurance companies hoping to profit from government subsidies—the fact that none of them ever tried to tell a single governor or legislator in any state in America that they might lose their subsidies if they did not set up an exchange on their own makes the alleged strategy here extremely puzzling. My colleague says he is inclined to agree with the federal judges who have found the case against the subsidies convincing. I am inclined to agree with the opinion of another federal judge, Harry Edwards: "it seems preposterous".