WASHINGTON — The U.S. Supreme Court appeared unlikely Thursday to change its long-standing rule that putting someone on trial more than once for the same crime does not violate the Constitution's protection against double jeopardy.

That outcome — keeping existing rules in place — would potentially be a blow to Paul Manafort, who faces prison time for violating federal fraud laws. A presidential pardon could keep him out of federal prison, but it would not free him from being prosecuted on similar state charges — unless the Supreme Court changes the rule. But that seemed did not seem possible after Thursday's oral argument before the justices.

Neither Manafort's case nor the work of Special Counsel Robert Mueller came up in the courtroom argument.

The Fifth Amendment provides that no person shall be "twice put in jeopardy of life or limb" for the same offense. But for nearly two centuries, the Supreme Court has repeatedly ruled that being prosecuted for the same crime once by a state and again in federal court, or the other way around, doesn't violate the provision because the states and the federal government are "separate sovereigns."

The lawyer for an Alabama man, Terance Gamble, urged the justices to overturn those earlier decisions. Convicted of robbery in 2008, Gamble was pulled over seven years later for a traffic violation. Police found a handgun in his car, and he was prosecuted under Alabama's law barring felons from possessing firearms. The local U.S. attorney then charged him with violating a similar federal law. Because of the added federal conviction, Gamble's prison sentence was extended by nearly three years.

"This is a 170-year-old rule that close to 30 justices have voted for," said Justice Elena Kagan. "You're asking us to throw it out because we think we can do better?"

Gamble's lawyer, Louis Chaiten of Cleveland, said the nation's founders understood the protection against double jeopardy to ban any second prosecution for the same offense. He said that under English common law, the roots of American law, there was no "separate sovereigns" exception. A person could not be put on trial in England if already tried for the same offense in another country.

But Justice Samuel Alito said changing the rule would block the U.S. government from prosecuting someone who attacked Americans overseas and was given only a light sentence by a foreign court.

"The logic of your position," Justice Brett Kavanaugh told Chaiten, "is that the U.S. couldn't prosecute someone like that even if it was important for national security."

And Justice Stephen Breyer said changing the rule would prevent the federal government from bringing civil rights cases when the states decline to prosecute or do so only half-heartedly.

The Trump administration urged the court to keep the current rule, arguing the state and the federal governments should be able to pursue their own interests without interfering with each other.

The court was originally scheduled to hear the case Wednesday, but Chief Justice John Roberts issued an order closing the court that day in observance of the national day of mourning for George H. W. Bush. The justices will issue their decision by late June.