California’s slow vote counting has frustrated political observers eagerly awaiting results, and handed Donald Trump and others an opportunity to claim “election rigging”. But experts say the system is working as designed: to protect against fraud and assure every vote is counted.

Within a day of the polls closing in California’s primary election this week, Trump started accusing Democrats of “trying to steal” the elections for the state’s governor and the mayor of Los Angeles. The justice department sent a federal prosecutor to observe the ballot-counting process in Los Angeles this week.

Republicans have lobbed such allegations against California for years, pointing to the state’s slowness in tallying ballots and the shifting results over the course of the counting as evidence of vote manipulation.

Prominent Democrats, including outgoing governor Gavin Newsom, are increasingly fretting that the state’s tortoise-like pace is becoming a liability for public confidence in elections in an era where conspiracy theories spread quickly through social media and can emanate straight from the White House.

But California’s vote-counting pace is actually a byproduct of a system of redundant verifications and opportunities for voters to fix errors. Every voter in California receives a mail-in ballot, and a vast majority of voters vote via mail. The signatures on those ballots are verified electronically and by human observers. When a ballot contains errors, the state gives voters 22 days to “cure” it.

The result is a system that is both highly accurate and resistant to letting small oversights devolve into trashed ballots. But in the state with the most registered voters by far, it comes at the cost of speed.

“There’s not a lot of people I know who would say: ‘Nah, I would rather have known who won the race faster than have my vote count,’” said Paul Mitchell, vice-president of the voter data firm Political Data Inc. “So what’s the rush? The focus should be making voting as easy as possible.”

“The only people who complain about it are the people who lose,” Mitchell added. “The conspiracy around it is really a conservative thing.”

Still, experts see obvious ways the system could improve. The legislature could invest the money that counties need to pay for staff, equipment and space to process ballots faster. The state assembly reduced the number of days a voter has to “cure” ballot errors from 26 to 22 last year. Cutting it further could substantially shorten wait times without severely inconveniencing voters, said Lisa Bryant, a political scientist at California State University, Fresno.

“California is very liberal on how much time they give people to cure those ballots,” Bryant said. “I think California could tighten up those timelines. That could help speed up the timelines without losing a lot.”

Election day itself creates the biggest bottleneck. A majority of the state’s voters use mail-in ballots for convenience, and voters have until election day itself to post them. Because many people still feel more secure depositing ballots at a polling site, a large segment of voters walk them in on election day instead of mailing them. But those votes can’t be counted until after election day, and they’re routed through a more time-consuming process.

The election day bottleneck was exacerbated this year by a uniquely tight gubernatorial race, in which many voters waited as long as possible to vote.

Some political observers hope that voters themselves can alleviate the problem by developing a culture of not waiting until the last minute to mail or walk in their ballots.

But dozens of counties have implemented a system in which voters open their walked-in ballots and cast them at the site, speeding up the process.

“It’s a great benefit for voters because they know their ballot has been counted,” said Kim Alexander, president of the California Voter Foundation. “They can walk away with confidence.”

California should pursue changes like those to preserve voter confidence, Alexander said. Waiting around for weeks to find out who won an election can erode trust in government, even if the delays have a clear explanation.

Regardless of whether or how California’s voting system changes, the state is likely to remain a target of specious allegations of fraud for the simple reason that it’s the site of competitive elections with national impact in a polarized era where a vocal minority has the capacity to spread disinformation quickly.

“Corrective messages don’t tend to go viral,” Bryant said. “It’s like hiking the Grand Canyon. They tell you to account for twice as much time going up as going down. It’s at least that much time trying to combat misinformation.”