The Department of Justice filed the appeal without waiting for a Federal Court of Appeals to evaluate another emergency request by the Trump administration to suspend a lower court order that temporarily froze the implementation of the rule, adding further confusion to the case just two months ahead of the midterms. On Thursday, the Justice Department asked the highest court to grant the USPS the authority to withhold the delivery of mail-in ballots—the latest episode in a lengthy legal battle sparked by an executive order signed by Trump last March, under the argument that mail-in voting causes widespread fraud in the country. The order assigns federal agencies an unprecedented role in electoral processes, which in the United States are managed by individual states. Among other provisions, the directive instructs the USPS to compile voter lists provided by various states and to send ballots exclusively to individuals included on those lists.

Voting rights advocacy groups and a coalition of 23 Democratic-led states challenged the order in federal court, arguing that neither the president nor the Postal Service should intervene in determining which mail-in ballots reach voters, leading a federal judge in Massachusetts to temporarily freeze the measure on August 27. North Carolina is expected to become the first state to distribute mail-in ballots on a massive scale for this year's elections, which will determine the balance of power in Congress for the remainder of Trump's term. The Supreme Court had previously lifted another order blocking Trump's plans on procedural grounds without ruling on the legality of the proposal itself.