The Supreme Court will decide whether states can count late-arriving mail ballots, which is Trump’s goal before the midterm elections

WASHINGTON (AP) — The Supreme Court agreed Monday to decide whether states can continue counting late-arriving mail ballots, which were a target of President Donald Trump.

The justices accepted an appeal from Mississippi after a three-judge panel nominated by the Republican president on the 5th U.S. Circuit Court of Appeals ruled last year that a state law allowing ballots arriving shortly after Election Day to be counted violated federal law.

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Mississippi is among 18 states and the District of Columbia that accept mail-in ballots received after Election Day as long as the ballots are postmarked on or before that date, according to the National Conference of State Legislatures.

The list includes swing states such as Nevada and states such as Colorado, Oregon and Utah that rely heavily on mail-in voting.

An additional 14 states allow late-arriving ballots from some eligible voters, including U.S. service members overseas and their families, to be counted, according to a filing from Democratic-led states that urged the justices to overturn the appellate ruling.

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The issue will be discussed in late winter or early spring. A final ruling will almost certainly come by late June, early enough to control the vote count in the 2026 midterm congressional elections.

Mississippi Attorney General Lynn Fitch, a Republican, told the Supreme Court that the appeal ruling “would have destabilizing ramifications nationwide” if it stands.

“The stakes are high: Ballots cast on Election Day — but not yet received — could swing close races and change the course of the country,” Fitch wrote.

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Trump claimed that the late arrival of ballots and the time-consuming process of counting the votes undermined confidence in the elections. In March, the Republican president signed an executive order on elections aimed at requiring that “votes be cast and received” by Election Day. The order has been challenged in court.

The Republican National Committee and the Mississippi Libertarian Party led the challenge to the Mississippi law. A federal judge rejected a similar challenge to Nevada’s law, but the decision was appealed.

The Supreme Court is separately considering reviving a lawsuit filed by Rep. Mike Bost, R-Ill., and backed by the Trump administration that challenges Illinois’ ballot receipt law. The issue is whether the congressman has the legal right to sue.

Some Republican-led states, including Kansas and North Dakota, have taken steps to stop counting late ballots. And in Ohio, Republican lawmakers are introducing legislation that would require ballots to be received by Election Day, closing the mail-in ballot window. The measure passed the state Senate.

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In the Mississippi case, Justice Andrew Oldham wrote for the appeals panel that Congress had designated a “unique” election day for members of Congress and presidential electors, “on which the electors must cast their ballots and their ballots must be received by state officials.” Justices James Ho and Stuart Kyle Duncan joined Oldham’s opinion invalidating the Mississippi law.

The ruling overturned a decision by U.S. District Judge Louis Guirola Jr., who held that there was no conflict between state and federal laws. “All that happens after Election Day is the delivery and counting of votes cast on or before Election Day,” wrote Guirola, who was nominated by Republican President George W. Bush.