The U.S. Postal Service (USPS) in August stopped updating its database of Americans who have changed their address, saying the failure to process “as least 1.8 million new changes of address” was due to an “inexplicable error,” TIME reported on Monday. The failure of the USPS system – which is used by nearly every U.S. state to keep their voter registration rolls up to date – could potentially compromise ability of those voters to cast ballots in November, as election officials gear-up for record-highs in mail-in voting.
While the agency said it had fixed the problem by mid-September, approximately half of U.S. states had already sent out mail-in ballot applications to registered voters. USPS spokesperson Martha Johnson told TIME that the system failure would not impact mail carriers’ from forwarding “eligible” mail to a voter’s new address now that the system is updated, but she did not address how the agency planned to deal with the fact that most states ban the forwarding of election ballots from an old address.
Internal USPS emails obtained by the magazine described the source of the failure as simply an unexplained “error.”
“Most state election offices also rely on the database to determine whether voters have moved, to ensure that ballots reach the new address and to purge voters who are no longer eligible to vote in the state,” the report stated. “In early September, several of the companies licensed to use the system alerted administrators that they were seeing drop-offs of as much as 95% in the number of changes of address for August, according to one vendor, who spoke on condition of anonymity because he did not want to damage his relationship with the postal service.”
“It’s a significant screw-up,” the vendor added.
The revelation is the latest in a string of controversies that have marred the reputation of the Postal Service under Postmaster General Louis DeJoy’s leadership.
One week ago, a federal judge in Manhattan halted the recent slew of operational and policy changes at the agency while directing USPS to treat all election-related mail as First-Class or Priority Mail in an effort to ensure that all votes are counted. In a separate lawsuit, another federal judge issued an injunction against USPS, preventing the agency from sending voters postcards about mail-in ballots that contained incorrect information.
Michael McDonald, a political science professor at the University of Florida who studies elections and methodology, told TIME that because each state oversees their own independent election, it would be a total “mess” to try and accurately quantify the number of voters that could be affected by the failure. He also noted that this issue could spark a rash of litigation.
“I can just see all the litigation after this. It just creates a mess,” McDonald said.
[image via Spencer Platt/Getty Images]