The Trump administration has asked the US Supreme Court, for the third time, to lift a lower court injunction blocking new US Postal Service rules that would let mail-in ballots be checked against state voter databases ahead of November's midterm elections. The move has alarmed Democrats and voting rights groups, who warn that the last-minute rule change could sow chaos, disenfranchise voters and represents federal overreach into a process traditionally run by individual states.

The USPS rules, issued in response to a Trump executive order from March, would allow the Postal Service to cross-check mail-in ballots against a central register of voters and reject those from people not listed. Solicitor General D. John Sauer called the injunction "baseless" and warned that delay risks confusion once ballots enter the postal system. Roughly a third of US voters cast ballots by post, and several states, including North Carolina, have already begun mailing them out. Critics, including the ACLU, argue the USPS has no constitutional authority over how states run elections, while a whistleblower report raised doubts about whether the underlying verification system even works.