Yesterday the Supreme Court declined to reconsider the "dual sovereignty" doctrine, which allows serial state and federal prosecutions for the same crime. Justice Neil Gorsuch dissented, arguing that historical evidence shows the practice is contrary to the original public understanding of the Fifth Amendment's Double Jeopardy Clause. By parting company with all of his colleagues except Ruth Bader Ginsburg, Gorsuch shows once again that he does not hesitate to take a stand in defense of civil liberties and the rights of the accused, even when it means reversing longstanding precedent.

In Gamble v. United States, a man with a felony record who was prosecuted under both state and federal law for illegally possessing a gun argued that convicting and punishing him twice for the same offense qualified as double jeopardy. Seven members of the Court disagreed, citing the familiar but puzzling logic of the dual sovereignty doctrine: Since two "separate sovereigns" had criminalized Gamble's conduct, it constituted two distinct offenses under the Double Jeopardy Clause. Notwithstanding appearances, then, he was not prosecuted twice "for the same offense."

Gorsuch gives that dodge the respect it deserves. "The government identifies no evidence suggesting that the framers understood the term 'same offence' to bear such a lawyerly sovereign-specific meaning," he notes. To the contrary, he says, British common law, the Fifth Amendment's history, contemporaneous legal commentary, and early court cases all indicate otherwise.

"Viewed from the perspective of an ordinary reader of the Fifth Amendment, whether at the time of its adoption or in our own time, none of this can come as a surprise," Gorsuch writes. "Imagine trying to explain the Court's separate sovereigns rule to a criminal defendant, then or now. Yes, you were sentenced to state prison for being a felon in possession of a firearm. And don't worry—the State can't prosecute you again. But a federal prosecutor can send you to prison again for exactly the same thing. What's more, that federal prosecutor may work hand-in-hand with the same state prosecutor who already went after you. They can share evidence and discuss what worked and what didn't the first time around. And the federal prosecutor can pursue you even if you were acquitted in the state case. None of that offends the Constitution's plain words protecting a person from being placed 'twice…in jeopardy of life or limb' for 'the same offence.' Really?"

Even if three additional justices had agreed with Gorsuch and Ginsburg, many cases that look an awful lot like double jeopardy would have continued to pass muster. Under the reasoning of the Court's 1932 ruling in Blockburger v. United States, two offenses are distinct when each "requires proof of a different element." In her dissent, Ginsburg notes that "in prosecutions based on the same conduct, federal and state prosecutors will often charge offenses having different elements, charges that, under Blockburger, will not trigger double jeopardy protection."

Hence a federal prosecutor who pursued hate crime charges against a racist or anti-Semitic mass shooter who was also tried for murder under state law would not have to worry about the Double Jeopardy Clause, since the federal case requires an additional element: The defendant chose his victims "because of" their membership in a racial, religious, or ethnic group. The same would be true if the Justice Department prosecuted police officers for violating someone's civil rights after they were acquitted in state court of using excessive force against him.

But in cases like this one, where the elements of the state and federal offenses are the same, a reinvigorated Double Jeopardy Clause would make a crucial difference. "A free society does not allow its government to try the same individual for the same crime until it's happy with the result," Gorsuch writes. "Unfortunately, the Court today endorses a colossal exception to this ancient rule against double jeopardy. My colleagues say that the federal government and each State are 'separate sovereigns' entitled to try the same person for the same crime. So if all the might of one 'sovereign' cannot succeed against the presumptively free individual, another may insist on the chance to try again. And if both manage to succeed, so much the better; they can add one punishment on top of the other. But this 'separate sovereigns exception' to the bar against double jeopardy finds no meaningful support in the text of the Constitution, its original public meaning, structure, or history. Instead, the Constitution promises all Americans that they will never suffer double jeopardy. I would enforce that guarantee."