That estimate is atop the typical number of mail ballots rejected for being late in three specific states: California, North Carolina, and Washington, which publish categorical information about late-arriving ballots. Elena Patel of the Brookings Institute published the report, which tries to project the effects of the Postal Service’s “Regional Transportation Optimization” initiative (RTO), in which rural mail can take extra time to deliver as it’s routed through “hubs:”
In this new analysis of the 2026 primaries in California, North Carolina, and Washington, I find that RTO exposure roughly doubled the rate at which mail ballots were rejected for arriving late. Rejections for every other reason did not move differently where RTO applies, and before RTO, the places it now covers rejected late ballots at about the same rate as places it does not, in both the two preceding federal primaries and across a decade of general elections nationally.
Using data from the 2022 and 2024 general elections, I estimate that roughly 40% of mail ballots returned by voters (16.6 million) come from places where the nearest post office is covered by RTO. If the same relationship holds in November, tens of thousands of additional ballots could be rejected for arriving late, against a recent average of about 115,000 late rejections. The remedy is not complicated. Voters in covered places can mail their ballots a few days earlier, consistent with what USPS has long advised. Knowing which places those are is harder. USPS and election officials should make that easy to find out.
Declare covered election officials as far back as February who were concerned about the RTO’s consequences for mail ballots, specifically in “postmark states” which count late-arriving ballots just as long as the USPS has indicated it took possession by Election Day. See: “Election Clerks Fearful That USPS Will Not Prioritize Mail Ballots,” “How Clerks Respond When D.C. Throws Them a Curveball,” and “House Republicans Ask USPS to ‘Reconsider’ Rule Affecting Mail Ballots,” all from Miranda Combs.
(Chris Deaton)