Chief Justice John Roberts’s one question during oral arguments challenging a central provision of Obamacare may turn out to be the most important. Drawing by Dana Verkouteren via AP

The Supreme Court oral argument on Wednesday in King v. Burwell featured thousands of words, dozens of provocative questions, two engaged and skillful lawyers—and one very striking silence. Chief Justice John Roberts, usually among the most active questioners on the court, scarcely said a word throughout the highly anticipated clash. The justices besieged Solicitor General Donald Verrilli and Michael Carvin, the lawyer for the plaintiffs, who are challenging a central provision of Obamacare, with so many questions that Roberts gave the pair ten extra minutes a side. The chief himself didn’t take up any of that time until practically the last moment.

Roberts’s one question may turn out to be extremely important. The issue in the case is whether the Obama Administration, in implementing the Affordable Care Act, violated the terms of that law. The plaintiffs assert that the A.C.A. only authorizes subsidies for individuals who buy health insurance on the fourteen state-run exchanges, or marketplaces. Under their reading of the law, the eight million or so people in the other thirty-six states who currently buy their insurance from the federal marketplace should be denied their subsidies. Most of the justices’ questions dealt with the issue of how to read the law correctly, but Roberts, in his single substantive question, took a different tack.

Anthony Kennedy had asked about “Chevron deference,” a doctrine of law that describes how much leeway the executive branch should have in interpreting laws. Verrilli, not surprisingly, said that the Chevron doctrine gave the Obama Administration more than adequate permission to read the law to allow subsidies on the federal exchange. “If you’re right about Chevron,” Roberts said, at long last, “that would indicate that a subsequent Administration could change that interpretation?” Perhaps it could, Verrilli conceded.

The question suggests a route out of the case for Roberts—and the potential for a victory for the Obama Administration. Roberts came of age as a young lawyer in the Reagan Administration, and there he developed a keen appreciation for the breadth of executive power under the Constitution. To limit the Obama Administration in this case would be to threaten the power of all Presidents, which Roberts may be loath to do. But he could vote to uphold Obama’s action in this case with a reminder that a new election is fast approaching, and Obamacare is sure to be a major point of contention between the parties. A decision in favor of Obama here could be a statement that a new President could undo the current President’s interpretation of Obamacare as soon as he (or she) took office in 2017. In other words, the future of Obamacare should be up to the voters, not the justices.

Roberts’s silence was the most unpredictable part of the argument. Carvin spoke first, and all four Democratic appointees —Ruth Bader Ginsburg, Stephen Breyer, Sonia Sotomayor, and Elena Kagan—battered him with hostile questions about his reading of the law. Based on their questions, and their voting patterns, they look extremely likely to vote to uphold the law in its current form. In a similar vein, Antonin Scalia and Samuel Alito went after Verrilli in a way that left little doubt about their sympathies. (Clarence Thomas, who has not asked a real question since 2006, can be assumed to be on their side as well.)

Alito is often the most clever questioner among the justices, and his intelligence and savvy were on display today as well. Verrilli and his allies have argued strongly that chaos would follow if the federal subsidies were struck down. Millions, they say, would lose their insurance virtually overnight. Alito offered a plan to alleviate that problem, if only for a little while. “Would it not be possible to stay the mandate until the end of the tax year,” he asked Verrilli, to avoid “very disruptive consequences”? Delaying the effect of a Supreme Court decision striking down the mandate would shift the political pressure away from the Court and toward Congress and the states. For colleagues (especially Roberts), who worry about the court as a focal point of partisan anger, Alito’s plan might offer hope.

For his part, Scalia looks ever more like a Fox News justice, who seems to get his talking points from popular culture rather than from the law. In response to Verrilli’s claim that millions would lose health insurance if the plaintiffs win, Scalia asked, in all seriousness, “You really think Congress is just going to sit there while all of these disastrous consequences ensue?… Congress adjusts, enacts a statute that takes care of the problem. It happens all the time. Why is that not going to happen here?” This is the point that several Republican members of Congress have made in recent weeks—“Sure! We’ll fix Obamacare!” As any half-aware student of the contemporary Congress knows, there is no chance at all—none—that this Congress will amend or improve the Affordable Care Act to save subsidies.

As for Anthony Kennedy, who is often described as the swing vote on this court, he offered hope to both sides. He seemed to suggest that the plaintiffs’ version of the law would impose undue obligations on the states—a favorite theme in Kennedy’s jurisprudence. At other points, however, he expressed sympathy for Carvin’s reading of the law, namely that it allowed subsidies only to those on the state-based exchanges. At a minimum, the votes of Roberts and Kennedy seem like they are in play—and that may be the best the Obama Administration could have hoped for at the outset of the day.