The United States Supreme Court has cleared the way for President Donald Trump to move ahead with his executive order restricting mail-in voting, though significant legal obstacles remain and it is uncertain how much his administration can implement before November's midterm elections. The court's 6-3 conservative majority lifted one of two existing injunctions that had blocked the order, with the three liberal justices dissenting. Justice Ketanji Brown Jackson wrote in a blistering dissent that the decision "needlessly injects chaos and uncertainty into the upcoming midterm elections."

Trump's executive order, signed in March, directs his administration to compile lists of eligible voters and instructs the US Postal Service to deliver mail ballots only to individuals on those lists. The Justice Department had filed an emergency appeal to the Supreme Court, arguing on procedural grounds that Democratic-led states had sued too early — before a final rule had been published. The court agreed on that narrow point, lifting the Massachusetts-based injunction on those grounds. However, a second nationwide injunction remains in place, meaning the administration cannot yet implement the changes. Late last week, the Postal Service released a final rule intended to carry out the order, and legal experts say that rule — which would allow the service to withhold ballot delivery to states that refuse to hand over voter lists — is now the central target for fresh litigation, potentially as soon as Tuesday.

Democratic officials in 23 states and Washington DC had sued to block the order, arguing that the US Constitution reserves the power to run elections to states and Congress, and that last-minute changes risked chaos and partisan manipulation. California Governor Gavin Newsom pledged to sue again immediately, calling the federal restrictions "Orwellian rules." California's legislature is also advancing two proposed laws that would create new felonies — punishable by up to four years in prison — for interfering with the delivery of mail ballots or seizing election records before results are certified. Oregon, which has conducted elections entirely by mail since 1998, also vowed to challenge any federal interference with its system.

The Supreme Court's ruling does not necessarily decide the broader constitutional questions. Legal experts note that the so-called Purcell principle — a judicial doctrine discouraging courts from changing election rules close to a vote — could cut both ways: it might be invoked to block further legal challenges to the new Postal Service rule, but it could equally be used to strike down the rule itself given how little time remains before some states begin sending ballots. The court ruled against Trump on a related mail-voting question in June, finding that states may count ballots arriving after Election Day.

Trump has long claimed, without credible evidence, that mail voting enables widespread fraud, including in his 2020 election loss to Democrat Joe Biden. Research contradicts that claim: a 2025 Brookings Institution study found roughly four cases of fraud per 10 million mail ballots cast. Mail voting has grown in popularity across party lines, accounting for approximately 30 percent of all ballots cast in the 2024 presidential election. The NAACP civil rights organisation, which filed a separate lawsuit in April, said the restrictions were designed to suppress turnout because Republicans "know full well that they are unpopular and will lose in a free and fair election" — a characterisation the administration rejects, framing the order as a necessary safeguard for election integrity.