The US Supreme Court has rejected President Donald Trump's effort to impose new restrictions on mail-in voting, delivering a significant legal defeat to the administration just weeks before November's midterm elections — the nationwide votes for control of Congress. The unsigned ruling, issued Monday with voting already underway in several states, allows states to continue operating their existing mail ballot systems without disruption.

The restrictions, which stemmed from an executive order Trump signed in March, would have required states to submit lists of eligible voters to an online portal and adopt a uniform ballot envelope style approved by the US Postal Service. The Postal Service would have been empowered to refuse to deliver ballots from states that did not comply. A whistleblower report raised serious concerns about the portal's reliability, warning that a single barcode error could result in entire batches of ballots being discarded, potentially leaving millions of voters without ballots. Critics, including 23 states and the District of Columbia that joined a legal challenge against the plan, argued that the Constitution grants the federal executive no authority to govern how elections are administered — a power that has traditionally rested with the states.

The Supreme Court's brief order stated that the administration was "unlikely to succeed on the merits" of its challenge to a lower court injunction blocking the rules, and that "the equitable factors applicable for obtaining emergency relief" did not support intervention. Justices Samuel Alito and Clarence Thomas dissented publicly; Alito argued that the Postal Service holds broad authority to regulate the mail and blamed the plaintiff states for the late timing of the legal challenge. Justice Brett Kavanaugh, appointed by Trump, voted with the majority but indicated in a concurrence that he could support the administration's position if the matter returns to the court outside of an election window. The court majority, as is standard for its emergency docket, did not elaborate on its reasoning.

The ruling was immediately welcomed by election officials and civil rights groups. States like Washington and Oregon — which conduct their elections almost entirely by mail — had faced potential chaos if the new rules had taken effect. Alabama, North Carolina, and Wisconsin had already begun dispatching ballots to voters while the new federal system was not yet functional. "Mail ballots have been protected for Colorado voters," said Colorado Secretary of State Jena Griswold. The NAACP's general counsel, Kristen Clarke, called the administration's effort "an 11th-hour attempt to hijack the way that we vote by mail."

Mail-in voting accounts for nearly one-third of all votes cast in the United States and is a legally established method in all 50 states. Trump has long claimed, without evidence, that the method is susceptible to widespread fraud, and has falsely attributed his 2020 defeat to Democratic challenger Joe Biden partly to mail ballot irregularities — claims that have been repeatedly rejected by courts and election authorities. Notably, Trump himself has voted by mail on multiple occasions, including as recently as this year. Voting rights advocates cautioned that Monday's ruling, while a relief, may not be the end of the matter. "This administration will keep testing every avenue to manipulate our elections," warned Samantha Tarazi of the Voting Rights Lab. "States run our elections — not the president."