Was there a late-game shift in the thinking of the Supreme Court on their Affordable Care Act ruling? That’s certainly the implication from this catch by Brad DeLong. Repeatedly in his opinion, Justice Antonin Scalia refers to Ruth Bader Ginsburg’s concurring opinion as a “dissent.” An example, which is littered throughout the text:

Our test’s premise of regulated activity is not invented out of whole cloth, but rests upon the Constitution’s requirement that it be commerce which is regulated. If all inactivity affecting commerce is commerce, commerce is everything. Ultimately the dissent is driven to saying that there is really no difference between action and inaction, ante, at 26, a proposition that has never recommended itself, neither to the law nor to common sense…

As I said, this happens over and over, nine times in the text. Now maybe this is just typical Scalia dismissiveness, but it’s also completely plausible that Ginsburg’s opinion WAS a dissent at one point, and Scalia’s concurring dissent originally the majority opinion. David Bernstein offers further grist for this mill with some gossip:

Back in May, there were rumors floating around relevant legal circles that a key vote was taking place, and that Roberts was feeling tremendous pressure from unidentified circles to vote to uphold the mandate. Did Roberts originally vote to invalidate the mandate on commerce clause grounds, and to invalidate the Medicaid expansion, and then decide later to accept the tax argument and essentially rewrite the Medicaid expansion (which, as I noted, citing Jonathan Cohn, was the sleeper issue in this case) to preserve it? If so, was he responding to the heat from President Obama and others, preemptively threatening to delegitimize the Court if it invalidated the ACA? The dissent, along with the surprising way that Roberts chose to uphold both the mandate and the Medicaid expansion, will inevitably feed the rumor mill.

Without that shift – if there was one – the entire Affordable Care Act would have been struck down, based on a reading that the individual mandate was both not a valid regulation of interstate commerce and also essential to regulating health care, such that the entire framework of the law, including Constitutional provisions, would have had to have been struck down. The claim for this is that the act’s other statutes would not have been enacted without the mandate, an effort by the Court’s four dissenters to read the minds of the White House and Congress.

But I’m more interested in what, if anything got to Roberts. Was Scalia’s opinion initially the majority ruling? Why did Roberts flip? It’s worth pointing out that Roberts’ opinion does invalidate the mandate under the Commerce Clause. That is a brand new piece of jurisprudence, and there are widely varying opinions from legal scholars over how much that will matter, i.e. whether it merely confines itself to the peculiar case in health care of “regulating inactivity” or not. So it could be that Roberts is chipping away at progressive governance post-New Deal and setting limits on federal power by inches at a time, or that he just couldn’t contemplate the invalidation of the entire law and opted for judicial restraint, or that he was moved by the impending attack on the legitimacy of the Court in the event of taking down the law, or even that he wanted to preserve a forced market for insurance companies and stave off the only option in the event of a full elimination of the law, a move to publicly-dispensed universal health insurance.

But it seems likely that he was moved by something.