WASHINGTON >> In the 2020 presidential election, Florida reported the results within a few hours of poll close of more than 99% of ballots cast.

In California, almost one-third of ballots were uncounted after election night. The state was making almost daily updates to its count through Dec. 3, a full month after Election Day.

This wasn’t unusual or unexpected.

California, the nation’s most populous state, is consistently among the slowest to report all its election results. Florida, the third-most populous state, is generally among the first to finish.

The Constitution sets out broad principles for electing a national government and leaves the details to the states. The choices made by state lawmakers and election officials as they sort out those details affect everything from how voters cast a ballot, how quickly the tabulation and release of results takes place, how elections are kept secure and how officials maintain voters’ confidence in the process.

How California counts

Lawmakers in California designed their elections to improve accessibility and increase turnout. Whether it’s automatically receiving a ballot at home, having up until Election Day to turn it in or having several days to address any problems that may arise with their ballot, Californians have a lot of time and opportunity to vote. It comes at the expense of knowing the final vote counts soon after polls close.

“Our priority is trying to maximize participation of actively registered voters,” said Democratic Assemblymember Marc Berman, who authored the 2021 bill that permanently switched the state to all-mail elections. “What that means is things are a little slower. But in a society that wants immediate gratification, I think our democracy is worth taking a little time to get it right and to create a system where everyone can participate.”

California, which has long had a culture of voting absentee, started moving toward all-mail elections last decade. All-mail systems will almost always prolong the count. Mail ballots require additional verification steps — each must be opened individually, validated and processed — so they can take longer to tabulate than ballots cast in person that are then fed into a scanner at a neighborhood polling place.

In 2016, California passed a bill allowing counties to opt in to all-mail elections before instituting it statewide on a temporary basis in 2020 and enshrining it in law in time for the 2022 elections.

Studies found that the earliest states to institute all-mail elections — Oregon and Washington — saw higher turnout. Mail ballots also increase the likelihood of a voter casting a complete ballot, according to Melissa Michelson, a political scientist and dean at California’s Menlo College who has written on voter mobilization.

In recent years, the thousands of California voters who drop off their mail ballots on Election Day created a bottleneck on election night. In the past five general elections, California has tabulated an average of 38% of its vote after Election Day. Two years ago, in the 2022 midterm elections, half the state’s votes were counted after Election Day.

Slower counts have come alongside later mail ballot deadlines. In 2015, California implemented its first postmark deadline, meaning that the state can count mail ballots that arrive after Election Day as long as the Postal Service receives the ballot by Election Day. Berman said the postmark deadline allows the state to treat the mailbox as a drop box in order to avoid punishing voters who cast their ballots properly but are affected by postal delays.

Initially, the law said ballots that arrived within three days of the election would be considered cast in time. This year, ballots may arrive up to a week after Election Day, so California won’t know how many ballots have been cast until Nov. 12. This deadline means that California will be counting ballots at least through that week because ballots arriving up to that point might still be valid.