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A panel of three Donald Trump-appointed judges said Friday that Mississippi violated federal law by counting mail-in ballots that arrived after Election Day but failed to block the policy before the election, in a ruling could still impact election-related lawsuits.

The 5th U.S. Circuit Court of Appeals ruling is a victory for the Republican National Committee and others who brought the case in Mississippi, a non-contested state with very little mail-in voting, and are seeking a ruling from a far-right district court friendly to their arguments.

“Voters deserve nothing less than a fair and transparent election that ends November 5th. We will continue to defend the law, fight to protect every legal vote and stop election interference in our nation’s most important election,” RNC Chairman Michael Whatley said in a statement celebrating the ruling.

Democrats and voting rights advocates fear a ruling in favor of Republicans will be used to increase challenges to late ballots in other states, which could make the difference when margins are tight in key elections.

“Congress has established by law a single 'day' for the election of members of Congress and the appointment of presidential electors,” the 5th Circuit panel said. “Text, precedent, and historical practice confirm that this 'Election Day' is the day on which ballots must both be cast by voters and received by state officials.”

States allowing late-arriving ballots include Nevada, Ohio and Virginia, as well as Maryland, which has a closely contested Senate race.

California and New York also allow ballots to be received after the election, both states that could make a big difference in the election of the party that controls the House of Representatives.

While the ruling has no immediate impact on the upcoming election, it could help advance any legal challenges Republicans plan to launch against any of the roughly 20 other states and jurisdictions that count ballots received after Election Day. Nevada's policies allowing late arrival of mail-in ballots are already being challenged by Republicans in state and federal courts, but courts in those cases have so far rejected those arguments.

Casting doubt on ballots that weren't counted until after Election Day was key to former President Trump's efforts to delegitimize and overturn the 2020 election. However, Friday's decision was careful to clarify that it was not an opinion on the actual counting of ballots after Election Day, but only on receipt.

“This does not mean that all ballots must be counted on Election Day,” the statement said. “Even if the ballots have not been counted, the result is clear when all ballots have been received and the proverbial ballot box is closed. The selection is complete and final. However, while the election workers are still receiving ballot papers, the election is still in progress: the result has not yet been determined as live ballot papers are still being received.”

“Although an individual voter made his final choice when he marked his ballot, the entire community must do so in order for the overall election to be completed,” the court added. “So the election ends when the final ballots are received and the electorate, not the individual voter, has voted.”

The 5th Circuit's decision is binding only on the three Southern states covered by the district court, and the panel is not ordering the policy blocked in Mississippi for the current election for now, but is instead sending the case back for further proceedings.

Justice Andrew Oldham, joined by Justices James Ho and Kyle Duncan in his opinion Friday, directed the lower court to “give due consideration to the value of maintaining the status quo in a voting case on the eve of an election,” as it did considered the next steps in this case. All three were appointed by Trump.

This story has been updated with additional details.