The Postal Service proposed a new rule pushing states to turn over their mail-in and absentee voter rolls to the agency, a move in line with President Donald Trump’s March executive order tightening regulations on mail-in voting in federal elections.

Since the start of his second administration, Trump has made election integrity and security a central issue, signing multiple executive orders to require proof of citizenship and crack down on mail-in voting fraud, essentially establishing a national voter verification system. His efforts have run into several legal hurdles, with judges ruling against requirements for proof of citizenship as Trump’s appeal pends, and several Democratic states sue over the mail-in voting order.

As the battle plays out in court, the USPS followed the White House’s order that the agency propose a rule outlining a method for each state and the postal carrier to agree on a list of voters eligible to receive mail-in and absentee ballots, and how mail-in ballots should be packaged. The agency’s proposed rule would create a “Mail-In and Absentee Participation List” in line with Trump’s request.

The state would first submit to the USPS a list of voters who are submitting mail-in ballots for that election, along with each voter’s corresponding personalized barcode on their ballots. Then, the USPS would return a final “Mail-In and Absentee Participation List” to each state’s chief election official to finalize the names of all enrolled voters in the state and the barcodes associated with their ballots.