That, in practice, would severely limit the scope of the protections of Section 2. On paper, those protections are themselves unchanged by the ruling. But for decades, private parties — including civil rights groups, individual voters and political parties — have brought Section 2 challenges on everything from redistricting to voter ID requirements.

“After reviewing the text, history, and structure of the Voting Rights Act, the district court concluded that private parties cannot enforce Section 2,” the judges wrote. “The enforcement power belonged solely to the Attorney General of the United States.”

The majority opinion from the three-judge panel of the St. Louis-based 8th Circuit was authored by Judge David Stras — an appointee of Donald Trump — and joined by Judge Raymond Gruender, a George W. Bush appointee. Chief Judge Lavenski Smith, another Bush appointee, dissented.

“The ruling has put the Voting Rights Act in jeopardy, and is very cavalierly tossing aside critical protections that voters have very much fought and died for,” said Sophia Lin Lakin, the director of the ACLU’s Voting Rights Project, who argued the case in front of the appellate court.

The decision originates in a racial gerrymandering case out of Arkansas, where the state chapter of the NAACP and others alleged that the state’s legislative districts violated the Voting Rights Act by diluting the voting power of Black voters. A lower-court judge, also a Trump appointee, ruled in early 2022 that he couldn’t decide the case on its merits because he found there was no private right of action — that, effectively, they had no right to bring the lawsuit. On Monday, the circuit court affirmed that finding.

The 8th Circuit covers Minnesota, Iowa, North Dakota, South Dakota, Nebraska, Missouri, and Arkansas. Appeals courts covering other states have proactively found a private right of action, with the circuit split making it very likely the Supreme Court will weigh in.

At least two Supreme Court justices have signaled an openness to the argument that non-governmental groups have no role in demanding enforcement of the Voting Rights Act.

In a 2021 ruling that made it harder to win on Section 2 claims, Justice Neil Gorsuch wrote in a concurring opinion that the court was explicitly not ruling on whether a private right exists.

“Our cases have assumed — without deciding — that the Voting Rights Act of 1965 furnishes” that right, he wrote. “Lower courts have treated this as an open question.” Justice Clarence Thomas concurred with Gorsuch’s opinion at the time.

A decision to bar private challenges under the Voting Rights Act would reverse decades of legal practice. Outside groups have repeatedly brought successful Section 2 challenges, and litigate alleged violations of the law far more frequently than the federal government does.

“We’re talking orders of magnitude of a difference in terms of enforcement of these rights,” Lakin said.

In a statement, Arkansas Attorney General Tim Griffin, a Republican, celebrated the ruling.

“For far too long, courts across the country have allowed political activists to file meritless lawsuits seeking to seize control of how states conduct elections and redistricting,” he said. “This decision confirms that enforcement of the Voting Rights Act should be handled by politically accountable officials and not by outside special interest groups.”

While the Department of Justice can — and under President Joe Biden, increasingly has — brought Section 2 challenges, private groups have been the main drivers of these lawsuits.

“It’s hard to overstate how important and detrimental this decision would be if allowed to stand,” Rick Hasen, a prominent election law expert at UCLA Law School, wrote on Monday. “If minority voters are going to continue to elect representatives of their choice, they are going to need private attorneys to bring those suits.”

Most recently, the Supreme Court sided this summer with a group of civil rights groups and individual voters who argued that Alabama’s congressional maps likely violated the Voting Rights Act — which led to the court-ordered creation of an additional majority-Black district next year. Thomas pointedly noted in his dissent in that case that the court had not addressed the private right of action question.

Other federal courts have also recently considered — and rejected — the argument that Section 2 of the Voting Rights Act does not have a private right of action. A ruling out of the 5th Circuit this month in a fight over Louisiana’s congressional lines noted that “there has not been frequent need in the circuit courts to analyze the issue” of a private right of action.

The court there wrote that the Supreme Court has at times expressly noted the ability of private parties to bring lawsuits, and other circuits have found that that right exists explicitly. The 5th Circuit judges ultimately held that a private right exists.

The immediate next step following Monday’s ruling was not immediately clear. Legal experts expect the case to end up in front of the Supreme Court. The Supreme Court could choose to hear an appeal directly, or the entirety of the 8th Circuit could weigh in on the case first. Lakin, the ACLU attorney, said early Monday afternoon that the challengers had not yet decided “our next step of actions.” But, she noted, the recent circuit split makes her believe the Supreme Court will “be interested in taking up the case.”