The U.S. Postal Service has introduced a controversial proposal that could impact millions of mail-in voters. This new rule would permit the Postal Service to withhold delivery of mail ballots in states not providing voter rolls to the federal government.

The rule suggests broad authority for the postal agency in the mail voting process, urging states to create lists of mail voters. These lists would enable Postal Service personnel to assess ballot eligibility. States refusing to cooperate might face a halt in their mail ballot services.

Opponents, including Democrats and voting-rights groups, argue this represents unconstitutional federal interference in state-run elections. They emphasize that withholding mail services where mail-in voting is prevalent could affect millions, particularly Democrats. Many Republicans, influenced by former President Trump’s claims questioning mail voting reliability, are not as reliant on this voting method.

Voter eligibility screening through mail ballots could represent an unprecedented federal role in election administration. Given the proposal’s ambiguity, the specific mechanics of this screening process remain unclear.

In a recent court hearing in Boston, a group comprising Democratic state attorneys general and voting rights organizations labeled the rule a federal encroachment on the voting process. The Constitution assigns this responsibility to states. They argued that with less than 150 days to the 2026 general election, meeting new requirements to establish voter lists and potentially redesign mail ballots would be costly and chaotic.

“It’s just difficult to overstate the disruption that this will cause to election administration,” stated Michael Cohen, California’s deputy attorney general, representing a coalition of states in the federal court.