Rejecting a Republican National Committee challenge, the Supreme Court ruled Monday that elections officials may count mail-in ballots that arrive after Election Day if they were postmarked beforehand.

The court, divided 5-4, held that the Mississippi law challenged by the RNC does not unlawfully conflict with the federal law that sets Election Day in early November.

The ruling, authored by Justice Amy Coney Barrett, is a setback for President Donald Trump, who has frequently criticized mail-in voting, claiming without offering evidence that it is rife with fraud. Two of the court’s conservatives were joined by the three liberals in the majority.

The decision avoids an election-year upheaval of state election laws. The Mississippi law and similar measures in 13 other states will remain in effect ahead of November’s midterm elections, when voters will decide which party controls the House and the Senate.

The laws in question allow late-arriving ballots to be counted as long as they were mailed by the Election Day deadline. California, New York and Texas are among the other states with such laws.

Read the full report from NBC News.