A coalition of 261 current and former Members of Congress filed an amicus brief with the U.S. Supreme Court on September 14, 2026, urging the high court to block a United States Postal Service rule that restricts mail-in voting access.
The Legal Challenge
The brief supports a lawsuit brought by a coalition of State Attorneys General in State of California, et al. v. United States Postal Service, et al. The plaintiffs argue that the challenged rule exceeds federal authority and violates constitutional limits on government power.
The rule stems from Executive Order 14399, issued by President Donald Trump. It requires states to provide a “citizenship verification list” before the USPS will process mail-in ballots for those residents. Critics argue the measure attempts to give the Postal Service control over voter eligibility, a power reserved for state and federal legislatures under Article I of the Constitution.
A federal court recently blocked the USPS from implementing the rule, citing lack of authority and unconstitutionality. The amicus brief argues that Executive Order 14399 violates separation of powers by usurping congressional authorities over election administration.
Bipartisan Congressional Support
The Senate Democratic Caucus joined the brief in full. It was led by Senator Alex Padilla, Senate Democratic Leader Chuck Schumer, Senator Dick Durbin, and Senator Gary Peters. In the House, Representative Joe Morelle, Representative Robert Garcia, Representative Joe Neguse, and Representative Jamie Raskin helped lead the effort.
Senators Jeff Merkley and Ron Wyden of Oregon were among the signatories. The coalition includes members from both parties, reflecting broad concern over federal interference in state election processes.
Political Context
Nearly one-third of Americans have voted by mail in recent elections. The timing of the challenge is significant, as it arrives weeks before the 2026 midterm elections.
“Millions of Americans cast their ballots with vote-by-mail, and Donald Trump is trying to make it harder for folks to vote just weeks before an election,” said Merkley.
“Donald Trump is plotting in plain sight to rig the upcoming election by weaponizing the Postal Service to undermine vote-by-mail in Oregon and nationwide,” said Wyden.
The controversy highlights a growing tension between the executive branch and state election officials. While President Trump voted by mail in Florida’s Republican primary in August 2026, his administration has moved to restrict the same mechanism for other voters through federal postal regulations.
The Supreme Court’s decision on whether to hear the case or enforce the lower court’s block will determine if the citizenship verification requirement takes effect. The outcome carries national implications for how elections are administered in 2026 and beyond.