The Supreme Court next week takes up the case of a small-time Alabama felon, Terance Gamble, who complains that his convictions by state and federal prosecutors for the same gun possession crime violate constitutional protections against double jeopardy.

But likely to be watching the proceedings closely will be those concerned about a big-time felon, Republican consultant and former Trump campaign chairman Paul Manafort, who was prosecuted by special counsel Robert S. Mueller III for tax fraud.

With President Trump keeping alive prospects that he might pardon Manafort, Gamble v. United States might be redubbed Manafort v. Mueller, joked Thomas C. Goldstein, an attorney who regularly argues before the Supreme Court.

The outcome in the case could affect nascent plans by states to prosecute Manafort under their own tax evasion laws — New York, in particular, has expressed interest — should Trump pardon Manafort on his federal convictions.

The Double Jeopardy Clause of the Constitution’s 5th Amendment prohibits more than one prosecution or punishment for the same offense. But the Supreme Court since the 1850s has made an exception, allowing successive prosecutions and punishments if one is brought by state prosecutors and the other by the federal government. (One early case from that time involved counterfeiting; another was prosecution of someone harboring a fugitive slave.)

In Gamble, the court is reconsidering these precedents. Almost none of the briefs filed in the case speculate on how a presidential pardon of a federal conviction would affect prosecutors at the state level should the so-called separate sovereigns doctrine be renounced.

But the issue is being debated loudly online. While Brett M. Kavanaugh’s nomination to the Supreme Court was pending, a theory emerged in some circles that the Trump administration was in a hurry to get him on the Supreme Court in time to have him participate in the case.

The reality of Gamble v. United States is more complicated than that. For one, the court accepted the case before Kavanaugh’s nomination. And it is unclear how the new justice would vote on the issue or whether he is pivotal to the outcome.

For another, Trump’s Justice Department urged the Supreme Court not to take the case. It says the status quo, allowing state and federal prosecutions, should remain in place.

That hasn’t stopped the speculation involving Manafort, who was convicted over the summer in Virginia of bank and tax fraud and in September pleaded guilty in D.C. to two other felonies as part of an agreement to cooperate with Mueller’s investigation into the Trump campaign’s contacts with Russian operatives. On Monday, the special counsel’s office said Manafort had breached his D.C. plea agreement by lying to investigators.

Speaking to reporters Thursday, Trump reiterated that he had not offered a pardon to Manafort but that he wasn’t taking it off the table. “I have never seen anybody treated so poorly,” he said of his former campaign chairman.

A spokesman for Manafort declined to comment for this story.

The real motivation for the court to reconsider the separate sovereigns doctrine came from liberal Justice Ruth Bader Ginsburg, who expressed the desire in an opinion two years ago. Her ally in that call? Conservative Justice Clarence Thomas.

“The double jeopardy proscription is intended to shield individuals from the harassment of multiple prosecutions for the same misconduct,” Ginsburg wrote in 2016. “Current ‘separate sovereigns’ doctrine hardly serves that objective.”

As the Ginsburg-Thomas alliance shows, concern about the doctrine is shared across the ideological divide.

“You see conservatives and liberals coming together on this issue,” said Brianne Gorod, chief counsel at the liberal Constitutional Accountability Center, who filed an amicus brief on Gamble’s behalf.

Their agreement reflects “a shared concern among many progressives and conservatives that there are profound problems in our criminal justice system — one manifestation of which is people being sentenced to jail time twice for the same offense, notwithstanding a constitutional provision designed to prevent exactly that,” Gorod said.

Because the states and federal government are separate sovereigns, the court has reasoned in the past, each has an interest in prosecuting someone for violating its laws, even for the exact same conduct.

The court recently signaled how seriously it is taking the question of overturning its precedent: It expanded the time allotted for oral argument. Besides hearing from Gamble’s lawyer, the court will hear separately from the Justice Department and the state of Texas, which heads a group of 36 states objecting to any change in the law.

Sherrilyn Ifill, president of the NAACP Legal Defense and Educational Fund, said at a preview of the Supreme Court term this fall that the case raises conflicting issues. On the one hand, successive prosecutions of the same offense seem unfair.

But on the other, it has been a handy tool for enforcing civil rights from the 1960s to more recent times. For instance, federal prosecutors brought charges against the Los Angeles police officers who beat motorist Rodney King in California after state trials ended in acquittals.

“The federal government possesses the solemn obligation to vigorously enforce the nation’s civil rights laws, including the relevant federal criminal civil rights laws,” says a brief filed by the Thurgood Marshall Civil Rights Center at the Howard University School of Law. “Consequently, any modification or abolition of the dual sovereignty doctrine will necessarily impact the future direction of federal criminal civil rights enforcement.”

The federal government and the states argue that they have their own laws to uphold and that they do not abuse the right.

“Each state has a strong interest in its sovereign power to prosecute violations of its laws regardless of the prosecutorial decisions of other sovereigns, whether the federal government or other states,” says a brief filed by Texas and 35 other states.

At the same time, more than 20 states have their own restrictions on prosecuting crimes for which an individual has already been prosecuted, as does the Department of Justice.

In its brief, the DOJ says it is better for state and local prosecutors to decide between themselves who should be responsible for a case. There is a federal policy saying the feds should step in after a state prosecution only where there is a significant national interest.

But Gamble’s lawyers say his case proves those protections don’t mean much; their client’s case held no special significance. “If the government believes that a ‘substantial federal interest’ is present in a [routine] gun possession case, when will the policy ever bar re-prosecution?” said lawyer Louis A. Chaiten, who represents Gamble.

The DOJ brief notes the power of the president to issue pardons affects only federal convictions. But would a ruling for Gamble make it impossible for states to bring charges against someone who received a pardon?

Not necessarily, said Gorod, as the specific elements of a state and federal case may be different.

“As an initial matter, a pardon on federal charges would, if anything, only block state prosecutions for the same offense,” she said. But the Supreme Court has explained in a previous case that “two offenses are not the same if each requires proof of a fact that the other does not.”