Sen. Bernie Sanders Bernie SandersSenate Republicans signal openness to working with Biden Hillicon Valley: DOJ indicts Chinese, Malaysian hackers accused of targeting over 100 organizations | GOP senators raise concerns over Oracle-TikTok deal | QAnon awareness jumps in new poll Schumer, Sanders call for Senate panel to address election security MORE (I-Vt.) is favored to win most of California’s 415 pledged delegates Tuesday, but the final results are likely to be unclear for days or even weeks to come.

California's notoriously slow vote-counting process is a function of the sheer size of its electorate, the processes by which voters get to cast their ballots, and the rules that govern the counts once those ballots are handed in.

In a statement last week, California Secretary of State Alex Padilla (D) warned that county elections officials are going to prioritize accuracy over speed.

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“In California, we prioritize the right to vote and election security over rushing the vote count,” Padilla said Thursday. “In most contests we will have a good picture of the outcome on election night. The outcomes of the closest contests may take days or weeks to settle.”

The counting will be of interest to Sanders and Joe Biden Joe BidenThe Memo: Warning signs flash for Trump on debates Senate Republicans signal openness to working with Biden National postal mail handlers union endorses Biden MORE given the possibility that a bounce from South Carolina could carry the former vice president to a stronger finish in California, which Sanders has long prioritized.

California has 20.7 million registered voters. Los Angeles County alone has 2.9 million registered Democrats, more than all the registered voters of Colorado.

Simply counting all those ballots takes a long time, but Californians also cast their ballots in a time-consuming way.

The vast majority of voters, about 80 percent, get their ballots in the mail, and about two-thirds of all votes are cast by mail.

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State law gives voters until election day itself to stamp and mail their ballots, and those ballots will be counted so long as they arrive at election offices by the Friday following Tuesday's elections.

This year, with such a large and fluctuating Democratic presidential field, there are signs that more voters are opting to hold their absentee ballots longer than they did in 2016, when Sanders and Hillary Clinton Hillary Diane Rodham ClintonBarr criticizes DOJ in speech declaring all agency power 'is invested in the attorney general' Virginia Democrat blasts Trump's 'appalling' remark about COVID-19 deaths in 'blue states' The Hill's Campaign Report: Biden asks if public can trust vaccine from Trump ahead of Election Day | Oklahoma health officials raised red flags before Trump rally MORE were the only viable candidates in the race.

Counties can begin opening vote-by-mail envelopes 10 days before the election, Padilla's office said, meaning the first batch of votes due out on Tuesday night will be from voters who cast their ballots long ago. Those batches will be from voters who had a clear favorite candidate on whom they settled months ago.

Previous state exit polls suggest that is good news for Sanders, who wins big margins among voters who decided he was their candidate weeks or months ago. And that probably means that Sanders's initial margins will slowly recede if a late surge by Biden materializes. Sanders is still likely to win — polls show he leads the state by a healthy margin — but his final result is likely to be smaller than the initial tallies show.

Even if Sanders runs away with the state, final estimates of how many delegates each candidate earns are likely to take days, if not weeks.

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More than half of the 494 delegates California will send to the national convention in Milwaukee, a total that also includes superdelegates, will be allocated by congressional district, and even if candidates such as Biden or Sen. Elizabeth Warren Elizabeth WarrenNo new taxes for the ultra rich — fix bad tax policy instead Democrats back away from quick reversal of Trump tax cuts It's time for newspapers to stop endorsing presidential candidates MORE (D-Mass.) reach 15 percent of the vote statewide, they will still have to clear that same eligibility threshold in each individual district to claim delegates.

The difference in a close district between 15.1 percent and 14.9 percent impacts not just whether Biden or Warren qualify for delegates, but how many delegates Sanders earns.

Unlike in Iowa, where the first votes were not publicly released until the day after the caucuses, we will definitely see some results Tuesday night. California counties are required by state law to send some results to Padilla's office within two hours of the polls closing.

Counties must report to Padilla's office how many ballots they have left to process by Thursday, two days after the polls close.

Rules that allow voters to register and vote on election day itself could create more delays. Those same-day registrants cast a provisional ballot, which is only counted after their home county determines they are actually eligible to vote. If voters run into any problems at the polls, they too can cast provisional ballots, which also requires counties to verify their eligibility.

All that adds up to a long count — and one that is baked into state law. California counties are given 30 days to complete their counts, a rule state elections administrators say is meant to ensure that every viable vote actually gets counted. After the April 3 deadline to certify, Padilla has another week to spot check before he, too, certifies the results on April 10.

“Several safety nets exist to protect voting rights, including Same Day Voter Registration, provisional ballots, and the postmark-plus-three days rule for vote-by-mail ballots. Every county is required to conduct a post-election audit of the results to ensure the accuracy and integrity of election results,” Padilla said. “In California, we'd rather get it right than get it fast.”