New system for screening mail-in ballots risks denying entire batches, says whistleblower

US senator says that project, a key part of Trump’s voting restrictions, is ‘perilously rushed and potentially unlawful’

A new system to screen millions of mail-in ballots for this November’s US midterm elections was thrown together so hastily, and tested so little, that a single scanning glitch could see entire batches of ballots turned away, a whistleblower has told Congress.

The project – a key part of Donald Trump’s new restrictions on voting – is “perilously rushed and potentially unlawful”, according to the US senator Richard Blumenthal, who disclosed the warning in a letter to David Steiner, the postmaster general, on Tuesday.

Blumenthal, the top Democrat on the US Senate’s permanent subcommittee on investigations, said the account he had received made clear the US Postal Service “lacks the technical or operational capability” to roll it out safely before ballots go out to voters.

The system stems from a March executive order by Trump tightening federal control over mail-in voting, directing USPS to check ballots against a federally approved voter list before sending them – a break from its usual role of simply delivering whatever is handed over by states. Courts have blocked and unblocked parts of the order repeatedly since, amid lawsuits arguing it oversteps into territory the constitution leaves to states.

USPS calls the result the “Federal Ballot Mail Portal”. Officials upload voter and barcode data in advance; clerks then scan a sample of arriving ballots – 15 to 400, depending on batch size – against that list. According to the whistleblower’s disclosure, the system runs on a “zero percent failure rate”: one mismatched scan rejects the entire batch, even if it holds tens of thousands of ballots.

Engineers had roughly three months, including a court-ordered pause, for work the whistleblower says would normally take close to a year. The full system was not even assembled for testing until about 24 August, the disclosure says, leaving only a handful of working days to catch problems before launch.

By the final week, officials were reportedly calling the effort “a shit show”, and one worker who raised concerns about the lack of testing time was told simply: “We cannot fail.”

About a third of voters cast ballots by mail in 2024. The whistleblower’s prediction of mass disruption remains unconfirmed – the system had not gone live as of this week.

“The whistleblower’s allegations make clear that USPS lacks the technical or operational capability needed to effectively implement the EO’s [executive order’s] provisions in a way that safeguards every citizen’s right to vote in the upcoming midterm elections,” Blumenthal wrote. “Despite this, the Trump Administration appears intent on USPS moving forward with its flawed plans, no matter the chaos they may create.”

Blumenthal’s letter also alleges USPS kept building the portal under active court orders to stop, including one issued on 27 August that remains in force. “USPS should have ceased all work on the Portal on June 25, 2026,” he wrote.

Blumenthal has given USPS until 4 September to answer questions, including who ordered the work to begin and resume, and until 8 September to hand over internal records. USPS has not disclosed an expected rejection rate, which the whistleblower says was withheld because it would expose how shaky the rollout is.

The representative Robert Garcia, the top Democrat on the House oversight committee, said his panel had received similar reports.

“This new secret tracking system at the US Postal Service is faulty, untested, and threatens to totally disrupt ballot delivery for millions of American citizens,” Garcia said, calling the policy an “unconstitutional and dangerous power grab”.