Presidential candidate Bernie Sanders is holding a rally Tuesday at the San Diego Convention Center, backing up his pledge to forge ahead with his campaign through the June 7 California primary and to the Democratic convention -- despite an uphill battle against Hillary Clinton 's growing lead in the delegate count.

The upcoming rally is the Vermont senator’s only official stop in California on this trip, and he’ll arrive in town after a day of campaigning in the West, including events in Utah, Idaho and Arizona, states that all have primaries on Tuesday. Polls show Sanders leading in Utah, but trailing Clinton in Arizona, while Idaho polls weren’t available.

Doors at the convention center open at 5 p.m. Tuesday, though the program isn’t expected to start until sometime later.The event is free and open to the public, but admission is first come, first served. Sanders’ campaign encouraged people who planned to attend to RSVP, but by mid-morning Monday his website had stopped accepting reservations.

The event will be held in Exhibition Halls D & E at the convention center at 111 W. Harbor Drive, San Diego. The Green Line Trolley stops outside of the venue at both First and Fifth avenues on Harbor Drive.

Sanders plans touch on several themes of his campaign, including getting big money out of politics, his plan to make public colleges and universities tuition-free, combating climate change and ensuring universal health care, according to his campaign.

Sanders’ rallies have drawn significant crowds. On Friday, in Tucson, Ariz., 7,000 people attended an event, while one in Seattle on Sunday had over 17,000, according to media reports. The two exhibition halls in San Diego have room for just over 10,000, seating charts show. It’s unclear if the Sanders campaign has made accommodations for overflow crowds.

According to The Associated Press, Clinton has a 314 pledged-delegate advantage over Sanders, and her lead grows to 755 when superdelegates are factored in. While he trails Clinton, Sanders has pulled off some surprises, including a March 8 upset victory in Michigan.

California has 548 delegates and as the second-to-last primary on June 7 (ahead of just Washington D.C.). Delegates are awarded proportionally.

Clinton won California in 2008 when her campaign secured 51.5 percent of the vote, besting then-Sen. Barack Obama , who received 43.2 percent. In San Diego County, 50 percent of voters supported Clinton while 44 percent backed Obama.

Clinton also claimed victories throughout Southern California, winning the eight southernmost counties in the region, losing Santa Barbara and San Luis Obispo counties. She also won most of the counties in the Central Valley, while Obama claimed victories in the Bay Area.

Ahead of his visit, Sanders is building momentum for a get-out-the-vote effort in California. On social media and his campaign website, he reminded potential supporters that they need to have either no party preference or register as a Democrat by May 23 in order to cast a ballot for him in the primary. He hasn’t set up a campaign office in San Diego, but he has a thick network of supporters and volunteers, from social clubs to phone banks.

View the photo gallery: Sanders rally at Convention Center