The Supreme Court on Thursday rebuffed the Republican Party and allowed a consent decree to go forward so that Rhode Island voters during the coronavirus pandemic could cast mail-in ballots without in-person witness verification.

It was the first time the justices had agreed to a pandemic-related voter relief effort. But they explained in a short, unsigned order that state officials had agreed to relax the rules and that the change already had been implemented during the June primary.

Unlike “similar cases where a state defends its own law, here the state election officials support the challenged decree, and no state official has expressed opposition,” the order said. “Under these circumstances, the applicants lack a cognizable interest in the state’s ability to enforce its duly enacted laws.”

The vote was not announced, but Justices Clarence Thomas, Samuel A. Alito Jr. and Neil M. Gorsuch noted that they would have granted the stay requested by the Republican National Committee and the state Republican Party.

Thursday’s ruling comes as President Trump, who is trailing his Democratic challenger in nationwide polls, continues to impugn mail-in voting. He and his political allies have said it is susceptible to large-scale fraud, but they have not shown evidence that is true.

Throughout the coronavirus crisis, when dealing with cases involving voting, prison conditions and gatherings such as religious services, the court has consistently sided with local officials rather than those who sought court relief.

Chief Justice John G. Roberts Jr. laid out his reasoning for that in one of the cases brought by a church objecting to California’s pandemic restrictions.

Local officials “should not be subject to second-guessing by an ‘unelected federal judiciary,’ which lacks the background, competence, and expertise to assess public health and is not accountable to the people,” he wrote, quoting a court precedent.

Rhode Island requires voters mailing their ballots to sign them in front of two witnesses or a notary. But Gov. Gina Raimondo (D) suspended that requirement for the June primary because of worries it would expose voters to the virus.

This summer, the legislature failed to reach agreement on a bill that would extend that accommodation to elections in September and November. Groups including Common Cause, the League of Women Voters and the American Civil Liberties Union sued, and state officials agreed in a consent decree not to enforce the witness requirement.

Then, Republicans sued. They alleged that the state had a history of fraud involving mail-in voting and that state officials must use the political, not judicial, process to make changes.

“The problems with federal courts enjoining valid state laws on the eve of elections do not go away just because some state defendants like the injunction,” wrote Thomas R. McCarthy, a lawyer for the Republicans. “A federal court has no power to enter a consent judgment that enjoins a state law unless that law is likely unconstitutional.”

The Republican request to the Supreme Court came after a panel of the U.S. Court of Appeals for the 1st Circuit denied the GOP’s challenge to U.S. District Judge Mary McElroy’s decision to allow the consent decree.

“The consent decree reflects the considered judgment of Rhode Island election officials that, in light of the COVID-19 pandemic, voters should not have to face a choice between their health and their fundamental right to vote,” the groups suing for the change told the Supreme Court.

Since the witness requirement was not used in the June primary, the Supreme Court’s order said, “many Rhode Island voters may well” believe it is not required for future elections.

John Marion, executive director of Common Cause Rhode Island, said the organization is “thrilled that the Supreme Court agreed not to stay the consent decree. Because of this order hundreds of thousands of Rhode Island voters will be able to safely cast their ballots without risking their health.”

The case is Republican National Committee v. Common Cause.

Rhode Island is one of two states with such extensive witness requirements. The other is Alabama. But the Supreme Court put on hold a judicial order granting similar relief in that state, where state officials had defended its need.