California voters will decide on Tuesday if they will remove Democratic Governor Gavin Newsom in the second gubernatorial recall in the state's history.
Polls opened at 7am Pacific time and will close at 8pm, but many Californians chose to vote by mail.
Voters are asked two questions in the special election: whether to keep Mr Newsom and, if he is removed from office, who should replace him.
If a majority of Californians vote “yes” to recall Mr Newsom, the top vote-winner in the second part of the ballot will become governor.
Radio talk show host Larry Elder, a Republican, is leading the field of 46 candidates running to replace Mr Newsom.
But recent polling suggests Mr Newsom is in a strong position heading into Tuesday's Republican-led recall. The “no” option leads “yes” by 15 points, a compilation of polls by FiveThirtyEight showed, meaning it would take an extraordinarily large polling error for Mr Newsom to lose.
Mr Newsom won his 2108 election over Republican John Cox in a landslide victory with more than 61 per cent of the vote. Democrats also hold the majority of state offices — both US senators, Alex Padilla and Barbara Feinstein, are Democrats, and both the minority and majority leaders in the House of Representatives - Republican Kevin McCarthy and Democrat Speaker of the House Nancy Pelosi, respectively - are from the state.
US President Joe Biden joined Mr Newsom at an event in Long Beach on Monday night to mobilise supporters. Vice President Kamala Harris, a former California senator, and former president Barack Obama have also campaigned for the governor.
The recall initiative, which has cost the state roughly $276 million, was sparked by Republicans angry with the governor's mask mandates and Covid-19 lockdowns. The petition gained traction after Mr Newsom was pictured having dinner at a restaurant, seemingly in breach of his own rules.
Mr Newsom and his supporters have portrayed the recall as a power grab by supporters of former president Donald Trump, emboldened by the Stop the Steal rally.
“We may have defeated Donald Trump, but we have not defeated Trumpism,” Mr Newsom said on Monday night.
Mr Biden said: “I'm going to make this as simple as I can. You either keep Gavin Newsom as your governor or you'll get Donald Trump.”
Mr Elder, who has openly supported Mr Trump, promised to repeal vaccine and mask mandates as the Delta variant rages in California. He has belittled women, derided the Black Lives Matter movement and is sceptical of climate change as the state continues to battle raging wildfires.
In recent days, Mr Elder has also questioned the integrity of the election results, suggesting “there may very well be shenanigans” in the recall, echoing Mr Trump's baseless fraud claims from the 2020 presidential election.
Mr Elder did not commit to accepting the results of the recall election during an interview with NBC on Monday.
In a statement released on Monday, Mr Trump insinuated the California recalled was rigged.
Much of the Republican criticism of California’s elections has focused on the wide use of mail-in ballots, which have been automatically sent to all active registered voters for state elections since the start of the coronavirus pandemic. About 8.6 million of the state's 22 million voters have already cast mail-in ballots for the recall vote.
The Elder campaign cried fraud at the weekend, complaining about a website that urges people to sign a petition saying he lost an election that was not over.
No widespread voter fraud issues have surfaced.
Arnold Schwarzenegger won California's first gubernatorial recall in 2003. He won re-election in 2006, the last time a Republican candidate won a statewide election in California.