Donald Trump has alleged without evidence that Democrats are cheating in California’s primaries and claimed in a late-night social media post that the US attorney’s office in Los Angeles was investigating.

As counting continues in the most populous state in the US, the president’s unfounded remarks are likely to further alarm election observers, who have warned of the risk of escalating misinformation in the absence of a final result.

Trump has a history of undermining election results that don’t go in his favor. He has repeatedly alleged that Democrats “stole” the 2020 presidential election, which he lost to Joe Biden, despite privately admitting his defeat, according to aides.

At 12.48am on Thursday, Trump posted: “The Dumocrats are at it again! They are trying to STEAL THE GOVERNOR OF CALIFORNIA PRIMARY, AND THE MAYOR OF LOS ANGELES, PRIMARY, AWAY FROM TWO GREAT REPUBLICAN CANDIDATES. Here we go with the very late and massive numbers of MAIL IN BALLOTS.”

“There’s BIG cheating by the Dumocrats in California,” he said 17 minutes later in another post on his Truth Social platform. “Votes are all tied up. May not be in for weeks. Under investigation by the U.S. Attorney’s Office in Los Angeles. Why the vote counting DELAY??? President DJT”.

The US attorney’s office said it had no comment on Trump’s claim that his allegations of cheating are “under investigation” by US attorneys. The Department of Justice in Washington DC did not immediately respond to a request for comment.

The president presented no substantive basis for questioning the legitimacy of the election.

Mail-in ballots factor heavily in California political races – typically about 80% of votes cast – and those ballots can be counted up to a week after election day, as long as they are postmarked before election day.

California uses a “jungle” primary process, in which the two candidates with the most votes advance to a runoff – regardless of their political party – unless one candidate wins an outright majority. A huge field of 61 candidates fragmented the vote in the race for governor, but Republicans have coalesced around Steve Hilton. Together with Xavier Becerra and Tom Steyer, the three are in a contest that remains too close to call as votes are tallied.

Mail-in ballots tend to favor Democrats, which implies the possibility that Hilton – whom Trump has endorsed – may drop into third place by the time all the ballots are counted.

The last Republican to win the California gubernatorial race was Arnold Schwarzenegger in 2006. Republicans have polled just under 40% in each of the last four contests.

Last month Gavin Newsom sent a letter to elections officials to thank them for their work while warning that a long process invites disingenuous accusations of misconduct.

“We must acknowledge that the longer the vote count takes, the more mis- and dis-information spreads,” wrote the California governor. “That means we must do all that we can to tabulate votes quickly and accurately. Time is of the essence in preventing election lies from taking root.”

On Wednesday evening, election observers echoed those concerns. “Conducting elections with integrity and ensuring that every eligible vote is counted are fundamental to maintaining public confidence in our democracy,” said Mike DuHaime of the Democracy Defense Project, a bipartisan effort to combat election misinformation.

“At the same time, prolonged delays in ballot tabulation, such as those that have become increasingly common in California, can undermine public trust and create unnecessary uncertainty around election outcomes,” DuHaime added. “The longer election results remain unresolved, the greater the opportunity for misinformation and speculation to spread online, eroding confidence in our electoral process. Accuracy must always remain the highest priority, but accuracy and timeliness are not mutually exclusive.”

A California man was charged Tuesday after authorities say he brought an explosive device and other weapons through a security checkpoint at Sacramento International Airport.

Kimani Osayande Jones, who also uses the last name Jackson, attempted to bring an improvised explosive device, a knife and other bladed weapons, a torch lighter and zip ties through a TSA security checkpoint on May 30, according to court documents filed Tuesday in the Eastern District of California.

Officials believe Jones, 49, repeatedly called the FBI tip line to report he was being threatened and intimidated in the months leading up to the incident.

Sacramento County Sheriff’s Office bomb technicians safely removed the explosive device and tested its powder and fuse, both of which were determined to be “viable and energetic,” officials say.

Investigators said the device had the potential to damage an aircraft and cause a loss of cabin pressure.

Jones’ other luggage, which had already been through security and loaded onto an American Airlines flight to Charlotte, North Carolina, was hand-searched and examined by a canine unit upon arrival, and investigators said nothing “illegal or concerning” was found.

Jones has been charged in federal court with unlawful possession of explosive material at an airport. He faces up to five years in prison and a $250,000 fine if convicted.

His attorney, Meghan McLoughlin, told CNN in a statement: “There is often more to these cases than the government’s allegations, and that the criminal process will reveal Mr. Jones’ story as well.”

Multiple cell phones and repeated FBI tip line calls

The Sacramento resident went through security on May 30 wearing a face covering and blue latex gloves, court documents say.

When officers found the explosive device and other items in Jones’ carry-on bag, he told them he was unaware the items were in his possession and said “he would be okay with just discarding them.” When authorities informed him that explosive material could not simply be thrown away, he denied ownership of the backpack.

Jones also had five mobile phones in his possession. The cameras on each phone had been covered with painter’s tape, which authorities believe was intended to prevent his surroundings from being recorded.

One phone contained a 15-minute timer ready to start and another had a message from an unknown number on the screen stating, “we will be awaiting your call,” according to court documents.

An individual police believe to be Jones made approximately 13 calls to the FBI tip line leading up to the incident, beginning in March.

On May 24, the caller reported being followed to and from a doctor’s appointment and described what he said were threats and intimidation by another individual.

He said he was “being coerced in sleep to say certain phrases through digital media” and described “hearing sounds coming through walls, window panes, or even outside, attributing the outside sounds to drones,” court documents say. The call was ultimately terminated because of its “nonsensical nature.”

On the day of the incident, the same caller again contacted the FBI tip line, alleging that several individuals were threatening him throughout the past year through “cyber means.” He also referenced exercising his Second Amendment rights while denying any intention to harm others.

The Sacramento County Sheriff’s Office also noted it had prior contact with Jones, “wherein he had a history of being paranoid.”

Although results from California’s primary election began rolling in on Tuesday, June 2, it could take days or even weeks before the final counts are certified. 

“This is normal … We have a process that by law ensures both voting rights and the integrity of elections, so I would call on all Californians to be patient,” Secretary of State Shirley N. Weber said in a June 2 news release.

The Golden State’s lengthy vote-counting process has “become a national narrative about California elections,” according to Thad Kousser, a professor of political science at the University of California, San Diego.

“In California, it takes a long time to certify votes, to verify the signatures, to then count the ballots; all of that process takes a while,” Kousser said in an interview last week. “It may take a while for us to learn who the top candidates who emerge are.”

Here are some factors behind California’s lengthy vote-counting process. 

Mail-in ballots come with added verification step 

With each mail-in ballot cast, elections officials must compare the signature on a returned vote-by-mail envelope to the voter’s signature on their voter registration card. Various factors go into determining whether the signatures match, including the slant of the signature, whether it is printed or written in cursive, and the size, proportions, or scale. 

Vote-by-mail ballots were Californians’ preferred voting method in both the 2024 primary and general elections, with drop-off locations — such as ballot drop boxes and voting centers — the most popular way to return mail-in ballots.