Toward the end of Wednesday’s oral arguments in the latest Obamacare case to make it to the Supreme Court, Donald Verrilli, U.S. Solicitor General, argued that the administration’s interpretation of the healthcare law was the most deferential to states. The argument, apart from coming from an administration that has consistently asserted a robust role for the federal government, was a bid to win over Justice Anthony Kennedy, a key swing vote, who raised concerns about the federalism implications of the suit.

At issue in the case, King v. Burwell, are the subsidies that the federal government provides for individuals buying insurance through Obamacare. The text of the Affordable Care Act says subsidies are to go to people obtaining insurance through an “exchange established by the state,” but an IRS rule subsequently said subsidies would also apply to exchanges set up by the federal government on behalf of states. Those challenging the law argue that the IRS acted illegally, and that Congress intentionally excluded exchanges set up by the feds so as to induce states to do it themselves; if they didn’t, their residents wouldn’t get subsidies.