While it went unmentioned at the oral argument, the case has implications for any presidential pardons that President Donald Trump might issue for those convicted by Special Counsel Robert Mueller. Under the status quo, states might still be able to prosecute under their own laws those who receive a presidential pardon, which applies only to federal charges.
Usual ideological pairings were scrambled as the court took a deep dive into the Double Jeopardy clause of the Constitution, which says no one shall be "subject for the same offense to be twice put in jeopardy of life or limb." The doctrine allowing dual prosecutions by state and federal prosecutors is an exception to the prohibition, recognized by the Supreme Court since the 19th century.
Liberal Justice Ruth Bader Ginsburg had called two years ago for a fresh look at the "separate sovereigns" doctrine, and described it Thursday as a "double-whammy" for criminal defendants. The colleague most outspoken in apparent agreement with her was conservative Justice Neil Gorsuch.
Most adament on the other side of the issue was conservative Justice Samuel Alito and liberal Justice Elena Kagan. Kagan demanded that Louis Chaiten, a Cleveland lawyer representing an Alabama felon, explain why the court should not apply its usual standard of letting decided issues stand, referred to as stare decisis.
"Part of what stare decisis is, is a kind of doctrine of humility where we say we are really uncomfortable throwing over 170-year-old rules that 30 justices have approved just because we think we can kind of do it better," Kagan said.
New Justice Brett Kavanaugh, who during his confirmation hearings was repeatedly questioned about whether he would abide by the court's established decisions, joined Kagan.
The formidable task for Chaiten, Kavanaugh said, was "not just to show that it's wrong but to show that it's grievously wrong, egregiously wrong." When there is uncertainty about the meaning of the constitutional prohibition, Kavanaugh said it was difficult to "clear that bar."
Chaiten said history was on his side. "This rule is egregiously wrong. It's a rule that - there was no practice for all of English history, no practice for the first century of this republic. That alone, I think, speaks volumes."
But Justice Sonia Sotomayor said that Chaiten's reliance on English law did not take into account the unique American system of governance, where both states and the federal government had an interest in seeing their laws enforced.
"Why is the doctrine wrong?" she asked.
Chaiten represents Terance Gamble, who was convicted of robbery in Mobile County, Alabama, in 2008 and two domestic violence charges in 2013. Under both state and federal law, such a convicted felon may not possess a firearm.
But police found one in Gamble's car when he was stopped in 2015. Gamble pled guilty to the state charges and was sentenced to a year in prison. But federal prosecutors also brought charges, and he received a lengthier sentence with that conviction.
Chaiten said that the dual prosecutions for such a routine gun possession charge disproved contentions by government prosecutors that they were used only in extraordinary cases.
Two years ago, in a concurring opinion in a related case, Ginsburg called for the court to reexamine its precedents allowing such prosecutions: "The double jeopardy proscription is intended to shield individuals from the harassment of multiple prosecutions for the same misconduct. Current 'separate sovereigns' doctrine hardly serves that objective." Justice Clarence Thomas joined her in that opinion, but was silent as usual during Thursday's hearing.
Ginsburg, though, repeated her concerns when questioning Department of Justice lawyer Eric Feigin, who was defending the doctrine.
"You have to concede, won't you, that this rule, this separate sovereign rule, has been widely criticized by both academics and federal judges?" she asked. Amicus briefs in the case have been filed by those on the left and the right.
When Feigin noted that federalism principles require allowing both federal and state prosecutors to enforce their own laws, Ginsburg and Gorsuch noted that federalism is usually invoked to protect individuals, rather than to empower governments at both levels.
Gorsuch said dual prosecutions may have been more limited when state and local officials were almost always presumed to take the lead.
"With the proliferation of federal crimes, I think over 4,000 statutes now and several hundred thousand regulations, the opportunity for the [federal] government to seek a successive prosecution if it's unhappy with even the most routine state prosecution is a problem," he said.
Feigin said there were only about 100 cases when federal prosecutors choose to bring charges when a state prosecution has preceded it. But he said the option was particularly important in civil rights cases. He noted federal and state charges have been brought in the Pittsburgh synagogue case, and the killings in an African-American church in Charleston.
He also said following Chaiten's interpretation about prosecutions would prohibit federal prosecution of overseas terrorism cases that injure or kill Americans, if foreign courts moved first.
The notion of how it would be decided which prosecution would come first seemed to bother Chief Justice John Roberts.
"Is it a race to the courthouse?" he asked Chaiten. "I mean, if a prosecution bars a subsequent one, the state and federal government may have different perspectives, is it whoever can empanel a jury first is going to block the others?"
Texas Solicitor General Kyle Hawkins said the status quo was working well, and meant that state and federal prosecutors cooperate rather than compete. He said he was representing 36 states, with about 86 percent of the country's population. He noted that 20 states bar prosecutions when there was already a federal conviction.
"The states may disagree with one another about various policy issues, but we are united here in urging the court not to overrule its long-standing interpretation of the Double Jeopardy Clause," he said.
The case is Gamble v. United States.