The Supreme Court justices had a lively discussion yesterday during arguments in King v. Burwell about who Congress intended to get health insurance subsidies and under what conditions.

The central question is whether the Internal Revenue Service had the authority to write a rule authorizing subsidies to go to millions of people in the 37 states now operating under federal exchanges.

The plaintiffs say the language of the law is clear: Subsidies are allowed in “an Exchange established by the State under [section] 1311of the Patient Protection and Affordable Care Act.” It doesn’t just say this once, but nine times in various linguistic forms.

The government argues that it is just a typo in legislative drafting: Congress clearly wanted subsidies to be available to citizens of all of the states, and the IRS therefore had the authority to write its rule authorizing subsidies in both federal and state exchanges.

Today, the Supreme Court heard oral arguments in King v. Burwell, a case with significant implications for the future of Obamacare. Most of the justices’ questions proceeded along expected lines. Most notable was a series of questions by Associate Justice Anthony Kennedy, who questioned whether it would be constitutional for Obamacare to induce states to set up exchanges. If Kennedy’s fears are right—that federal subsidies for state-based exchanges are “coercive”—then he might side with the Obama administration in the case. But if you understand how Obamacare’s insurance markets work, it’s clear that Kennedy should side with Obama’s challengers.

Justice Anthony Kennedy said state insurance exchanges could collapse without federal subsidies to offset the costs of insurance

Supreme Court heard an hour of oral arguments in an Obamacare challenge, will cast votes Friday, and release a decision this summer

Conservatives say law was written to deny subsidies to people in states that decided not to set up their own insurance marketplaces

The White House insists Congress meant to treat everyone equally

As many as 8 million people could lose their insurance without the subsidies, which lower the cost of insurance
GOP wants to replace subsidies with temporary financial assistance, and then new state-based systems they say would be more competitive

White House is ‘quite pleased’ with its solicitor general’s arguments