Ms. Klobuchar, who campaigned at several stops in Nevada over the weekend, was holding a campaign fund-raiser Monday night in Los Angeles.
At his California rally, Mr. Sanders also took on his other critics in the party. “The Democratic establishment is getting nervous,” he said. “They say, ‘Oh, Bernie can’t win the election.’ Take a look at this crowd today.”
“What the establishment is trembling about right now — they are crying on television — what they are trembling in fear for is that working people are standing up demanding decent wages,” he added.
Mr. Sanders made his remarks at the former Ford Assembly Plant in Richmond, an automotive factory that was shuttered in 1955, to a crowd of more than 6,000 attendees. Thousands more crowded outside and watched through the building’s glass walls.
Mr. Sanders addressed the region’s housing crisis and high rates of homelessness. “It is a moral obscenity that in our country tonight, 500,000 people will sleep out on the streets,” he said. “Together we end that obscenity.”
As early voting sites opened in Las Vegas on Monday, Senator Jacky Rosen, Democrat of Nevada, joined a line of more than 50 people and waited to cast her vote. Ms. Rosen — who defeated a Republican incumbent in 2018 with the help of endorsements from Mr. Biden, Mr. Sanders and Ms. Warren — declined to indicate whom she favored.
“Every Democrat who’s running, they’re going to return decency, dignity, respect and civility to the White House,” Ms. Rosen said in an interview outside the culinary union, which is hosting an early voting site. “They’re going to have compassion with whatever health care plan they put forward, they’re going to worry about our environment and our future.”
“Any Democrat on that ticket, I’m going to get behind that nominee,” she added. “I’m voting uncommitted.”
Thomas Kaplan reported from Reno, Kate Conger from Richmond, Calif., and Reid J. Epstein from Washington. Trip Gabriel contributed reporting from Elko, Nev., and Astead W. Herndon and Rebecca R. Ruiz from Las Vegas.