The rule, which the Postal Service finalized in August, requires states to notify the agency at least 90 days before a federal election whether they intend to allow ballots to be sent by mail, and to submit a list of voters planning to vote by mail at least 60 days before the election. The U.S. Supreme Court blocked the agency from enforcing it for this year's midterms, but that decision applied only to the 2026 elections, leaving the rule's long-term fate unresolved.

With the midterms concluded, opponents have shifted to direct pressure on the Postal Service. At a news conference in Washington, D.C., on Tuesday, American Postal Workers Union President Jonathan Smith argued that allowing the policy to stand while litigation continues would damage public trust in the agency.

"We should not allow a policy that threatens public confidence in the Postal Service neutrality to remain in place while its long-term status is debated in court," Smith said.

Chelsey Wininger, executive director of the Democratic Association of Secretaries of State, framed the rule as an attempt to federalize control over ballot access. "This executive order is trying to force federal control over who can and cannot receive a ballot in the mail," she said at the same event.

The stakes are highest in the eight states that authorize all-mail elections: California, Colorado, Hawaii, Nevada, Oregon, Utah, Vermont and Washington state. Nationwide, at least 33.9 million mail ballots were cast in the November general election, according to the University of Florida Election Lab.

Trump signed the executive order in March directing Postmaster General David Steiner to propose the rule. The order also required the Department of Homeland Security, with assistance from the Social Security Administration, to compile a list of voting-age U.S. citizens in each state and provide it to state officials at least 60 days before federal elections, without specifying how states should use the data.

The Postal Service declined to answer questions Thursday, citing pending litigation. In its August statement publishing the final rule, the agency said the policy does not make it an election administrator or dictate how states run elections, noting that states retain complete control over voter rolls and decide who may vote by mail. The agency described the rule as consistent with the Constitution.

Supporters, including the Trump administration and Republican officials in 11 states, argued the rule would add security safeguards against fraud. Missouri Secretary of State Denny Hoskins wrote in an August court declaration that the rule "would help bolster the security of mail voting in Missouri and reduce the risk of fraud." The other states backing the rule were Alabama, Florida, Indiana, Kansas, Louisiana, Montana, Nebraska, Oklahoma, South Carolina and South Dakota. Hoskins' office did not respond to an interview request this week, and the White House did not respond to a request for comment.

Democratic-led states sued in the spring, arguing the rule encroaches on their constitutional authority to administer elections. U.S. District Judge Indira Talwani, an Obama appointee in Massachusetts, issued a preliminary injunction halting implementation, which the Supreme Court declined to block. Justice Brett Kavanaugh, who joined the decision to pause the rule for the midterms, wrote in a concurring opinion that there was "at least a fair prospect" the rule falls within the Postal Service's authority — a signal that the legal fight is far from settled.

At a Postal Service Board of Governors meeting on Tuesday, board members did not discuss the mail ballot rule, according to a recording posted to the agency's website. The meeting focused largely on the agency's difficult financial condition, and Steiner praised postal workers for their performance during the election.

"In this election, the USPS did exactly what we always do," Steiner said. "We put our heads down and we got the job done."