Sen. Bernie Sanders’s full-bore campaign for president comes to Irvine and two other Southern California locations this weekend, with the candidate expected to attract thousands of fervent supporters.

Undaunted by Hillary Clinton’s near-certainty of winning the Democratic nomination, Sanders continues campaign like a candidate who can prevail while his aides negotiate for a larger role in drawing up the party platform at the national convention in July.

“We are in until the last ballot is cast,” Sanders said at Tuesday rally in Carson.

His weekend itinerary includes a Saturday evening rally in National City, a Sunday afternoon rally in Vista and a 6 p.m. event at the Irvine Meadows Amphitheatre, which seats 16,000. Sanders also plans a 10 a.m. rally Tuesday at the Anaheim Convention Center. Details can be found on Sanders’ campaign website.

Also Tuesday, Clinton plans to visit the Inland Empire with a stop at UC Riverside. Details can be found on her website.

Republican nominee Donald Trump had to turn away attendees after filling Costa Mesa’s 8,000-seat Pacific Amphitheatre for rally last month.

While many supporters are holding out hope that he can win the nomination, even those who say he’s unlikely to win the necessary delegates remain ardent supporters of Sanders and his campaign.

“Hillary should be continued to be pressed to the left, and Bernie being in the race has helped that since the beginning,” said Fullerton College theater major Kevin Lee Christensen, who’s headed to Columbia University in the fall.

Christensen cited Sanders’ opposition to the Iraq war, his refusal to take contributions from Wall Street and his opposition to fracking as key attributes. Other Orange County supporters listed his support for universal health care, free college tuition and a $15 per hour national minimum wage.

“He has already changed the direction of the country,” said Alex Milledge, who is graduating Saturday from CSU Fullerton with a bachelor’s degree in Philosophy and Religious Studies. “I think he has awakened the American people to the corruption of our system. It used to be conspiratorial to think that elections are rigged and politicians are bought by corporations. Now it’s plain to see.”

Clinton has 2,293 pledged delegates and superdelegates and needs 90 more to win the nomination, although superdelegates can change their allegiance at any time. Sanders has 1,533 pledged delegates and superdelegates.

California’s June 7 primary will distribute 475 delegates on a congressional district by congressional district basis.

Sanders has won 11 of the last 19 contests and has shown no signs of backing down despite growing concern among some Democrats that his ongoing battle could hurt Democrats in a Clinton-Trump matchup,

After sounding subdued if not downbeat about the race for weeks, Sanders has resumed a combative posture against Clinton, demanding on Wednesday that she debate him before the June 7 primary in California.

On Tuesday, Sanders said the party faced a choice to remain ‘”dependent on big-money campaign contributions and be a party with limited participation and limited energy'” or ‘”welcome into the party people who are prepared to fight for real economic and social change.'”

According to his advisors, Sanders has been buoyed by a stream of polls showing him beating Trump by larger margins than Clinton in some battleground states, and by his belief that an upset victory in California could have a psychological impact on convention delegates who already have doubts about Clinton.

But his newly resolute attitude is also the cumulative result of months of anger at the national Democratic Party over a debate schedule that his campaign said favored Clinton, a fundraising arrangement between the party and the Clinton campaign, the appointment of fierce Clinton partisans as leaders of important convention committees, and the party’s rebuke of Sanders on Tuesday for not clearly condemning a melee at the Nevada Democratic convention on Saturday.

The New York Times contributed to this story.