It takes more time to verify and count mailed-in ballots than those marked at polling places. So, as voting by mail continues to gain popularity, close electoral outcomes will increasingly take longer to finalize.
Over the past 12-15 years, the state's limits on who can vote by mail have gradually been relaxed, to the point where now just about anyone who wants to can obtain permanent vote by mail status. Sonoma County Registrar of Voters Janice Atkinson says she's seen a surge in those voters locally.
A few years ago, at the request of some concerned voters, Sonoma County adopted a double envelope system for mail-in ballots, so the verifying signatures are not exposed while the ballot is in the mail. That additional layer of security means an extra step when the ballots are counted, Atkinson explains, although the process is now partially computerized.
When that process is combined with the growing number of vote-by-mail ballots that don't arrive until Election Day, Atkinson says the result will be longer intervals to determine the final outcome of very close contests.