Warner, Kaine, Colleagues Urge Supreme Court to Block Postal Service Rule Limiting Mail-In Voting

WASHINGTON – U.S. Sens. Mark R. Warner and Tim Kaine (both D-VA) joined a bipartisan, bicameral group of lawmakers and former lawmakers in filing an amicus brief with the U.S. Supreme Court in the case of State of California, et al. v. United States Postal Service, et al. The lawsuit, brought by a coalition of state attorneys general, including Virginia’s Attorney General Jay Jones, challenges the legality of President Trump’s executive order and U.S. Postal Service rule seeking to exert control over mail-in ballots ahead of the 2026 midterm elections. Specifically, the case challenges a final rule issued by the USPS pursuant to Trump’s directive that imposes unconstitutional and unworkable restrictions on mail-in voting, including requiring states to provide a “citizenship verification list” and attempting to give USPS control over who can vote by mail. Nearly one-third of Americans have voted by mail in recent elections — a voting practice Trump himself used as recently as August 2026 , when he voted in Florida’s Republican primary. In the court filing, the amici curiae argue that Trump’s Executive Order 14399 and USPS’s final rule violate the separation of powers and usurp congressional authorities outlined in Article I of the U.S. Constitution, which gives the States and Congress exclusive authority over election administration. “As current and former legislators, amici took an oath to uphold and defend the Constitution of the United States — including its guarantee of the separation of powers,” wrote the lawmakers . “Amici have a particular interest in defending the institutional role of the Legislative Branch under Article I of the Constitution and in vindicating the long-settled principle that the Constitution commits ultimate regulatory authority over federal elections to Congress. The Constitution does not contemplate the Executive Branch acting unilaterally to assert power over federal elections. Yet that is what the Order and Final Rule do.” The amici also pointed to a recent federal court ruling blocking the USPS from implementing its newly finalized mail ballot rule for the midterm elections, saying the agency lacked the authority to implement the rule and that its actions are “ substantively unconstitutional and contrary to law .” “The district court correctly concluded that Appellees are likely to succeed on the merits of their claims that USPS lacked authority to issue the Final Rule, that the Final Rule unconstitutionally imposes mail-ballot requirements on the States, and that the Final Rule unconstitutionally bars non-compliant State and local election officials from using the USPS to mail ballots at all,” wrote the lawmakers. The lawmakers concluded by asserting States’ power to administer elections and Congress’s power to make or alter rules regulating elections, which the Supreme Court itself has described as an “ override ” authority. Trump’s illegal incursion on this authority is an attempt to disenfranchise people who depend on mail-in ballots to vote. “The integrity of our constitutional system depends on each branch keeping to its assigned role,” concluded the lawmakers . “The Framers set up a two-part system that gave the States default authority to regulate federal elections subject to Congress’s authority to override the States. The Framers did not provide the President with any authority to interfere in that system, nor has Congress subsequently imbued the President or the Executive Branch with any such authority by statute.” In addition to Sens. Warner and Kaine, the amicus brief was filed by 259 lawmakers and former lawmakers, including the entire Senate Democratic Caucus. Sens. Warner and Kaine have been pushing back on the Trump administration’s attempts to “take over” and “nationalize” our upcoming elections. Fighting to ensure the safety and security of our midterms and protect Americans’ constitutional right to vote, the senators have repeatedly demanded that USPS abandon its proposed rule to implement President Trump’s unconstitutional executive order to restrict voting by mail. The full brief is available here . ### * High-quality photographs of Sen. Mark R. Warner are available for download here * Photos may be used online and in print, and can be attributed to ‘The Office of Sen. Mark R. Warner