Most, but not all, local election measures and races seem decided, as every few days more ballots are counted and the results made public.

But county election officials have until Dec. 3, and the secretary of state has until Dec. 13, to certify the results, so it’s possible some of these results will remain up in the air for weeks to come.

Why does it take so long and why does California, and by extension Santa Cruz County, lag the rest of the nation in processing ballots? It’s not inconsequential, since control of the House of Representatives remains in doubt, even though Republicans are expected to end up with a slim majority of seats that would give the party control of both the Senate and House.

But election rules were put in place to ensure voting is easy, with every registered voter since 2020 receiving a mail-in ballot.

California has more than 22 million registered voters. That’s more people than the total population of 47 other states. And since voters don’t have to request a ballot, it becomes extremely difficult to project how many will actually be returned.

Ballots can be returned by mail or at dropboxes or polling places. In Santa Cruz County, about 76% of the ballots have been counted, or 129,156 voters. Of these only about 9% cast their votes in person; the rest were by mail, according to the county Elections Department.

While in most states, ballots must be received by the close of Election Day to be counted, in California ballots are valid as long as they’ve been postmarked no later than Election Day and are received within seven days of the closing of polls.

California registered voters who receive their mail-in ballot can choose to vote in person, but must cast a provisional ballot if they don’t bring their mail-in ballot to the polling place. Provisional ballots aren’t counted until election officials verify the voter hasn’t already voted by mail.

In addition, signatures on mail ballots must be verified, and if they don’t match the signatures on file, county election officials are obliged to try to contact those voters to verify their signatures. Since mail-in ballots require a number of verification steps, provisional ballots aren’t tallied until later,

And it’s even more complicated, since voters can register at any polling place or designated center in the state as late as Election Day. If a voter is in line by at least 8 p.m. that day, when polls close, they can still vote. If poll workers cannot confirm they are eligible, they receive a provisional vote.

All this explains why an estimated 2.6 million ballots as of Tuesday still had be processed in California, according to the secretary of state. This includes 350,722 conditional ballots, 75,531 provisional ones and at least 161,477 needing to be “cured” by a voter because of an error. Voters have until Dec. 1 to ensure their ballots are not in error.

Six of the 13 House races yet to be called are in California. In recent elections, candidates in state and local races have seen modest leads on election night shrink and often dramatically change as days pass and more ballots are processed. The long counting process has in the recent past cast doubts, however unwarranted, on election integrity in extremely tight races.

Many states have finished counting before California officials even have all the ballots in hand. Other large states, including New York, Texas and Florida typically count the vast majority of their ballots on the night of the election. As of last weekend, those three had each reported counting 97% or more of votes cast. Pennsylvania, the country’s fifth most populous state, typically takes longer to count votes, but it had reported 98.5% of the vote by Saturday.

There remain a few, possibly undecided, results for Santa Cruz County.

One is the election of a new supervisor for the 2nd District, where Kim De Serpa is likely to win, maintaining a narrow lead over Capitola Mayor Kristen Brown, with a number of votes still to be counted. As of Tuesday at 4 p.m., when 3,295 more votes were released, De Serpa had 12,397 votes, or 50.93%, while Brown was at 11,708 votes or 48.1%. Monica Martinez has clearly been elected in the 5th District. The next vote update is set for 4 p.m. Friday.