Bernie Sanders spoke to tens of thousands of people in California ahead of that state’s primary election on Super Tuesday, when the remaining field of Democratic presidential candidates will compete for a share of nearly a third of all delegates to select the nominee to face Donald Trump in a general election.

More than 1,300 delegate votes are up for grabs on Tuesday, with 415 of them coming from California. Thirteen other states – including delegate-rich state Texas – and American Samoa will also hold their primary elections on 3 March. Ahead of that contest, Mr Sanders addressed packed rallies in San Jose and Los Angeles on Sunday.

He told an estimated 24,000 supporters in Los Angeles: “With your help on Tuesday, we’re going to win the Democratic primary here in California. With your help, we’re going to win the Democratic nomination, and with your help, we are going to defeat the most dangerous president in modern history.”

With some polls giving him a double-digit lead in the state, Mr Sanders’ win in California and elsewhere on Super Tuesday would solidify his candidacy as a status quo-breaking frontrunner that the Democratic Party will have difficulty edging out in the weeks ahead.

The campaign announced a massive fundraising effort in February, raising nearly $47m (£36m) from more than 2.2 million individual donations.

Democratic candidates compete on the campaign trail: In pictures Show all 18 1 /18 Democratic candidates compete on the campaign trail: In pictures Democratic candidates compete on the campaign trail: In pictures Jessica Canicosa, a precinct captain for Bernie Sanders, waits to greet caucus voters at Liberty High School in Henderson, Nevada REUTERS Democratic candidates compete on the campaign trail: In pictures Hotel workers at the Bellagio in Las Vegas get to grips with voting papers during the Nevada caucuses AFP via Getty Images Democratic candidates compete on the campaign trail: In pictures A caricature of Bernie Sanders is projected on to a tree during a rally in Las Vegas EPA Democratic candidates compete on the campaign trail: In pictures A woman waits to have a photo taken with Elizabeth Warren during a town hall meeting in Las Vegas REUTERS Democratic candidates compete on the campaign trail: In pictures The threat of coronavirus and other germ-borne illnesses was on some voters' minds at the Democratic caucuses in Henderson, Nevada Getty Images Democratic candidates compete on the campaign trail: In pictures Former vice-president Joe Biden takes a selfie with a voter in Las Vegas ahead of the Nevada caucuses REUTERS Democratic candidates compete on the campaign trail: In pictures Amy Klobuchar changes her shoes backstage after giving a speech in Exeter, New Hampshire AFP/Getty Democratic candidates compete on the campaign trail: In pictures A warmly-wrapped-up dog attends an Elizabeth Warren event at Amherst Elementary School in Nashua, New Hampshire AFP/Getty Democratic candidates compete on the campaign trail: In pictures Bernie Sanders, who romped to victory in New Hampshire against Hillary Clinton in 2016, talks to the media in Manchester Getty Democratic candidates compete on the campaign trail: In pictures Joe Biden was hoping to improve on his poor showing in Iowa in the New Hampshire primary Reuters Democratic candidates compete on the campaign trail: In pictures Elizabeth Warren, renowned for giving time to supporters for selfies, works the crowd at the University of New Hampshire in Durham Getty Democratic candidates compete on the campaign trail: In pictures Joe Biden takes a selfie with a supporter and his child outside a campaign event in Somersworth, New Hampshire on 5 February Reuters Democratic candidates compete on the campaign trail: In pictures Elizabeth Warren and Bernie Sanders quarrel after a confrontation in a TV debate in which Sanders claimed that Warren was not telling the truth about a conversation in which she claimed he had said a woman could not win the presidency on 14 January AP Democratic candidates compete on the campaign trail: In pictures Supporter Pat Provencher listens to Pete Buttigieg in Laconia, New Hampshire on 4 February Getty Democratic candidates compete on the campaign trail: In pictures Pete Buttigieg speaks at a campaign event in Concord, New Hampshire while awaiting the results of the Iowa caucus Reuters Democratic candidates compete on the campaign trail: In pictures Elizabeth Warren is presented with a balloon effigy of herself at a campaign event in Nashua, New Hampshire on 5 February Reuters Democratic candidates compete on the campaign trail: In pictures A Trump supporter rides past a rally for Amy Klobuchar in Des Moines, Iowa on 14 January AP Democratic candidates compete on the campaign trail: In pictures A man holds up a sign criticising billionaires in the presidential race in front of Michael Bloomberg in Compton, Califronia. The former New York mayor skipped the first caucus in Iowa and instead campaigned in California on 3 February Reuters

Volunteers knocked on a reported 1 million doors in California, and the campaign added 100 staff members and opened 23 offices in the state, banking on a significant win in the state to show his strength in the primaries ahead and at the voting booth in November.

At his Los Angeles rally, he said: “All across this country, the American people are saying ‘no’. We will not have a pathological liar in the White House for four more years. We will not have a corrupt administration for four more years. We will not have a president who has apparently not read the constitution of the United States.”

Moments before Sanders appeared on stage, Pete Buttigieg – who attracted early support as a moderate alternative to Joe Biden – announced his withdrawal from the race, urging unity among candidates in order to defeat the president, and implying a united front to remove Mr Sanders from the race. Mr Sanders’ opponents have attacked him as an ideologue or have raised red scares against his social democrat platform.

But that effort will meet the ferocity of a campaign with unmatched grassroots support, as Mr Sanders and his supporters point to a multi-racial and class-conscious coalition of Americans who are backing the candidate and, more crucially, his platform, which stands in stark contrast to his Democratic rivals.

Even in the event of a loss, the campaign is betting on the motivation of millions of Americans to continue campaigning for his signature Medicare for All healthcare plan, a Green New Deal, free public college, debt cancellation and a range of other policy proposals that have galvanised his supporters around the rallying cry and campaign slogan of: “Not me, us.”

In Los Angeles, he said: “The political establishment – you are making them very nervous ... They are seeing workers stand up and demand decent wages, young people rise up and demand a higher education without going in debt, [people] are believing health care is a right, not a privilege. The fossil fuel industry [is] catching on that the American people understand that short-term profits are not more important than the future of our planet.”

His institutional Democratic support in California is more rare. The state’s current and former governors have not endorsed a candidate, and neither has Kamala Harris, the state’s star senator who dropped out of the presidential race late last year. Senator Dianne Feinstein endorsed the former vice president to little if any fanfare or surprise.

In Los Angeles, Mr Sanders also introduced comedian Sarah Silverman, Chuck D from the hip-hop group Public Enemy and 94-year-old acting legend Dick Van Dyke, among a host of high-profile endorsements. Other backers include Alexandria Ocasio-Cortez, who campaigned for him in 2016, and scores of musicians and comedians who have performed smaller fundraising shows across the US.

Van Dyke recently filmed an advert for the campaign urging older voters to back the 78-year-old candidate, who has struggled to capture the support of people aged 65 and older. In the ad, the 94-year-old actor jokes that: “I think somebody younger, like Bernie, is just a perfect candidate.”

“I never saw Bernie as a career politician,” he told the crowd in Los Angeles. “I just saw him as a patriot who worked hard.”