The consultation was driven by Republicans angered by measures taken by Newson against Covid-19, such as the use of masks or imposing restrictions.
Many Californians chose to vote by mail and have until Tuesday night to send their ballot in which they must first answer if they want to remove Newson and then who should replace him.
To stay in office, Newson needs to win more than 50% of the vote.
If he does not succeed, the candidate with the most votes will replace him regardless of the number of votes received.
After a weak start, Newson, a 53-year-old telegenic ex-mayor of San Francisco, seems on his way to salvage the trance. Polling site fivethirtyeight.com predicted Tuesday that he would win 53.7% of the vote and therefore remain in office.
Democratic President Joe Biden himself flew to California on Monday to express his support for him and warn voters that removing him runs the risk of a Donald Trump-type governor taking over.
“They keep Gavin Newson as governor or install a Donald Trump,” Biden said at a rally in Long Beach.
“Voting no (to impeachment) will protect California from Trump. The option should be very clear,” he added.
Newson also appealed to mention the former Republican president, a hated figure in California, where the number of registered Democrats is twice that of Republicans.
“In California Trumpism is still in the election,” he said.
His main challenger is Larry Elder, a 69-year-old right-wing political commentator who has openly supported Trump.
Elder is at the helm of a diverse pool of hopefuls including a cannabis advisor, a former San Diego mayor, and TV star Caitlyn Jenner.
Also competing is John Cox, who was a Republican candidate for governor of California in the 2018 elections and widely defeated by Newson.
Democrats say the poll is an attempt by Republicans to hijack the state government and seize power as they could not at the polls.
Although Newsom won comfortably in 2018, California election rules make it easy to call recall referenda.
To do this, only 12% of the number of voters in the previous election must be signed. In this case, the number was 1.5 million in a state of 40 million inhabitants.
This referendum is only the second in California history.
The first made actor Arnold Schwarzenegger governor in 2003.
Schwarzenegger, who ended up in office for more than seven years, was the last Republican governor of California.
The onslaught to remove Newson gained strength when he saw images of a dinner in a restaurant apparently ignoring his own rules against Covid-19, which earned him many calling him a hypocrite.