Three days after Californians headed to the polls, key races in the primary election remained too close to call and experts warned the counting could continue for days.

In the governor’s race, the British-born conservative pundit Steve Hilton was narrowly leading with an estimated 60% of ballots counted by Friday morning. Xavier Becerra, a former US health and human services secretary under Joe Biden, followed closely behind, and billionaire Tom Steyer trailed behind the pair. The top two vote-getters will advance to the general election in November.

Los Angeles mayor Karen Bass learned on Tuesday evening that she would be advancing to defend her seat, but it remains unclear whether she’ll be facing former reality TV star Spencer Pratt or progressive city councillor Nithya Raman. With an estimated 65% of votes counted, Pratt was leading Raman.

The rankings could still change significantly, and residents may have to wait weeks to learn who will face off in November. Per state law, California counties must finish counting ballots by 15 June, but certain ballots are exempt from that deadline. For example, mail-in ballots postmarked by election day and received by 9 June are valid and can be processed beyond the deadline.

Experts expect many of the untallied votes to lean Democratic. That’s because Republicans are more likely to return their ballots early or vote in person on election day. Those ballots get counted first. A larger than usual number of Democrats waited until the last minute this year to cast their vote as they weighed which candidate had the best chance of reaching one of the top two slots.

“What compounds things this time around is that Democrats have been holding on to their ballots,” said Richard Hasen, a University of California, Los Angeles law professor.

Still, the ongoing tabulation did not stop Donald Trump from declaring victory for his favored candidate. The president congratulated Hilton, accused the state of election rigging and said the Department of Justice would open an investigation. It’s unclear if the justice department has done so.

“We don’t want cheating in our elections. You see it in California. Those numbers are coming down rapidly. They found a lot of mail-in ballots last night, shockingly. We don’t want that,” Trump said in the Oval Office on Thursday.

The office of Gavin Newsom, the California governor, posted a clip of a CNN video explaining how the nation’s most populous state prioritizes accuracy and accessibility over speed.

“For the record: we wish the votes were counted faster, too,” Newsom’s office posted.

Last year, Newsom signed a bill requiring the vote count to be completed within 13 days, rather than the previous 30 days. To get an extension, counties must inform the secretary of state’s office of the reason for the delay.

Marc Berman, a Democratic state assemblymember who wrote the bill to accelerate ballot counting, said Trump’s comments about the counting process were disappointing and “a lie”.

“While Trump is laser focused on lying about our elections and undermining voters’ faith in our democracy, so that Republicans can then try to pass policies like Voter ID laws that make it harder for people to vote, our priority is to make sure that every validly cast ballot is counted,” he said in a statement.

In a video posted on X, Hilton criticized the state’s counting as “just another shambles brought to you by California Democrats”. But he also said that so far his campaign has seen nothing to indicate it will need to go to court.

Several congressional races are still too close to call. In California’s sixth congressional district, one that was remade to give Democrats an advantage, Kevin Kiley, a former Republican and now independent congressman, was in the lead. Republican Michael Stansfield was in second place, just ahead of Democrat Richard Pan, a former state lawmaker, with tens of thousands of votes left to tally.

The Associated Press contributed reporting