The concerns, raised during internal meetings on how to carry out a March executive order from President Donald Trump, surfaced as a separate anonymous federal employee filed a whistleblower complaint with U.S. Sen. Richard Blumenthal describing the system as untested, error-prone, and capable of triggering mass disenfranchisement before the midterms.
How the Mail Ballot System Would Work
Trump’s March executive order directed the Postal Service to draft new regulations requiring states to hand over lists of every voter eligible to receive a ballot by mail. USPS would then use those lists to decide which ballots actually get sent to voters — a role historically controlled by state and local election officials.
To carry out the directive, USPS officials were tasked with building a new portal for states to upload voter information and back-end software that would let mail delivery sites and local post offices track, and potentially block, ballots entering the mail stream on their way to voters.
The Batch-Rejection Problem
Inside the meetings, a repeated worry was how to avoid invalidating an entire batch of ballots if a single voter among thousands could not be confirmed as eligible, according to a person familiar with the discussions who spoke on the condition of anonymity out of fear of reprisals. Some officials recommended limiting harm by not rejecting whole batches.
Despite those internal cautions, the final rule moved forward with a directive to reject entire batches containing even one unverified ballot, according to the whistleblower who contacted Blumenthal.
“As presently designed, if even one bar code on one single ballot in a bulk-mailing of 10,000 ballots fails to properly scan during the verification process, the entire batch is rejected and sent back to the state — effectively stopping the ballots from being mailed to voters,” the whistleblower wrote.
The stakes were made concrete at a mid-August National Association of Election Officials conference in Kansas City, Missouri, where election clerks raised concerns directly to USPS officials just days before the final rule was issued. An attendee cited Maricopa County, Arizona, which routinely sends out more than 2 million ballots in its initial mailing. USPS officials confirmed that one ballot with a bad barcode or wrong voter information within that 2 million-plus batch could delay the entire mailing, according to two people who sat in on the committee meeting.
Courts Have Temporarily Blocked the Rules
Voting rights organizations, state officials, and Democratic political groups have filed lawsuits challenging the new mail voting rules. A federal court has temporarily blocked the requirements for states, and the merits of the rule are expected to reach the Supreme Court before the November election.
Even if the Supreme Court allows the plan, election officials and experts say the system cannot be ready in time. Ballots for military and overseas voters must go out this month, and the technical infrastructure remains unfinished.
The Postal Service has defended its final rule in court, stating it does not intend to seize control of election administration and that the rule “need not and should not prevent a single voter from voting by mail.” A USPS spokesperson told ProPublica the agency is carefully reviewing the Blumenthal whistleblower’s concerns and has spent months developing the system consistent with court orders, with instructions for election officials coming soon.
“Regardless of political party or perspective, we share a common goal: ensuring that Americans can have confidence that their election mail will be handled securely and delivered reliably,” the spokesperson said.
White House and Industry Response
White House spokesperson Lauren Bis said in a statement that building software to carry out the new mail ballot checks “is neither complex nor unique for USPS since the Postal Service regularly uses bulk mailing and intelligent mail barcodes for a wide variety of large customers.”
“Under President Trump, the federal government is working to ensure safe, transparent, and honest elections,” Bis wrote.
Industry experts disagree. Jeff Ellington, CEO of Runbeck Election Services, which prints ballots and ballot envelopes for counties, told ProPublica that seemingly small unresolved details — such as what file format to use when uploading voter lists and whether to provide mailing or residential addresses to USPS — could throw the entire system into chaos.
“These are trivial things that create massive problems,” Ellington said. He added that most counties in the country lack the type of barcodes needed to make the system function, and that USPS has not told local election officials how to design new ballot envelopes and get them approved within such a compressed timeframe.
Whistleblower Alleges Work Proceeded Under Injunctions
The Blumenthal whistleblower also alleges that the administration moved forward with steps to build the new system during two initial court injunctions — which would have violated the court’s order. USPS had stated when issuing its final rule that it was adhering to the injunctions and would not take actions to implement the rule for the 2026 election unless the injunctions were lifted.
Both the whistleblower and the person familiar with the internal discussions said a sophisticated tracking system of this kind would typically take at least nine months to build. Workers began in mid-June and were given a Sept. 1 deadline, leaving only weeks. The whistleblower’s disclosure also flagged that while most systems carry a known error rate, USPS has adopted a “zero-percent failure policy” with no internal acknowledgment that errors will occur.
Blumenthal, the Connecticut Democrat, asked the postmaster general for detailed information about the plan in a letter this week. On a Monday call with reporters, he said the new USPS rule puts all mail voters at risk and accused the administration of being “hellbent on changing the framework of casting ballots in this country, clearly for political reasons.”
What Happens Next
The Supreme Court’s decision on whether to lift the lower-court injunction will determine whether states must begin uploading voter lists to the new USPS portal in the coming weeks. A ruling that greenlights the mail ballot system would force election officials to retrofit envelopes, adopt compatible barcodes, and integrate with an untested tracking infrastructure under extreme time pressure.
Watch for Blumenthal’s postmaster general response, additional whistleblower disclosures, and whether election officials in large jurisdictions such as Maricopa County publicly detail how the batch-rejection rule would affect their mailings. Litigation in lower courts and any further injunctions will also shape whether the Trump executive order’s mail voting rules take effect for the midterms or remain on hold.
— Sofia Alvarez, government desk, AXO News