The U.S. Postal Service has issued a proposed rule that would allow it to refuse delivery of mail ballots from states that do not provide voter roll data to the federal government. Published on June 2, the rule sets new requirements for states to compile lists of mail voters that Postal Service personnel would use to verify the eligibility of ballots before they enter the mail system. If states decline to comply, the Postal Service could withhold delivery of their mail ballots.

The rule, which is currently open for a 30-day public comment period, reflects an executive order signed by former President Donald Trump in March that directed the Postal Service to condition election mail delivery on states’ cooperation with federal voter data requests. The final rule is expected by the end of July.

Critics, including Democratic officials and voting rights advocates, argue that the proposal represents an unconstitutional federal intrusion into state-managed elections, which the Constitution entrusts primarily to the states. They warn that blocking mail ballots could disrupt election administration and disenfranchise millions of voters, particularly in states where mail voting is heavily used. Many observers note that Democrats are more likely to vote by mail, while Republicans have been increasingly skeptical of mail balloting following unsubstantiated fraud claims promoted by Trump and his allies.

In legal arguments before a federal judge in Boston last week, a coalition of Democratic state attorneys general and voting rights groups contended that the rule’s requirements to create new voter lists and potentially alter ballot designs would be costly, complicated, and hard to implement with fewer than 150 days before the 2026 general election. California’s Deputy Attorney General Michael Cohen described the proposal as potentially causing significant disruption to election processes.

Supporters within the Trump administration defended the policy as a necessary step to enhance election security. The Department of Justice, represented by attorney Stephen M. Pezzi, acknowledged continuing uncertainties around how the rule would be implemented but pushed back against demands for immediate judicial intervention.

The rule calls for the Postal Service to use a “Mail-in and Absentee Participation List” to cross-check ballots before accepting them for delivery. Ballots that do not match this list or that fail to meet new envelope and tracking standards could be rejected and returned to voters for correction. This kind of pre-mail screening of ballots by a federal agency has been unprecedented, with responsibility for verifying ballots traditionally residing with state and local election officials.

Postmaster General David Steiner previously stated that the Postal Service does not intend to compile voter lists itself but would deliver ballots based on lists provided by states. However, the proposed rule suggests a much more active federal role in screening ballots, which postal experts warn could create mail processing bottlenecks, delay ballot delivery, and disrupt voting timelines.

Legal challenges have already been filed against the executive order underpinning the rule, with opponents arguing it represents an unconstitutional federal overreach. A federal judge in May declined to block the order pending further developments, citing the hypothetical nature of potential harm since the rule had not yet been finalized or implemented.

The proposed changes would not affect primary elections or mail ballots for overseas and military voters but would impose new standards for mail ballot envelopes and require states to cooperate fully with Postal Service directives to ensure ballot delivery.

Observers note that the rule is part of broader efforts by Trump and Republican lawmakers to tighten control over mail voting ahead of the midterm elections, despite minimal evidence of election fraud. Democrats have characterized the efforts as politically motivated attempts to suppress voter turnout under the guise of protecting election integrity.

The Postal Service did not provide comment on the proposed rule. The 20-page document sets the stage for potential changes that could reshape the federal postal service’s role in the administration of mail-in voting across the United States.