County election managers change the zip code of 31,000 voters on September 3. Ballots go out that week. Those 31,000 are undeliverable. Someone collects those valid ballots. On September 15th, those addresses are quietly changed back.

National Change of Address Database (NCOA) will not pick up those address changes. They didn’t happen because there is no history.

The 31,000 citizens were getting their mail just fine — except for ballots. Ballot addresses were driven by the county mail-in ballot database — the one that was changed, then changed back.