Bernie Sanders Questions Donald Trump's Wealth: 'He Is Probably as Broke as Everybody Else' At a San Diego-area rally, the Vermont senator questioned Trump's wealth.

 -- Donald Trump's seemingly lavish lifestyle may include private jets, yachts and penthouse apartments, but Bernie Sanders isn't so sure that the presumptive GOP presidential nominee is as wealthy as he suggests.

At a campaign event Saturday at Kimball Park in National City, California, Sanders told the crowd of thousands, Trump "tells us is he is a billionaire. Who knows? He is probably as broke as everybody else is.”

The Democratic presidential hopeful, who is campaigning in Southern California ahead of the state's June 7 primary, has expressed similar doubts in the past. At Saturday's rally, Sanders said Trump "doesn’t often tell the truth," and that includes claims about his wealth.

But as ABC News previously reported, Trump took in at least $619 million last year, according to an ABC News analysis of Trump's personal financial disclosure documents. He continues to refuse to release his full tax returns despite calls from both sides of the aisle to make them public, citing an ongoing audit. Trump has said repeatedly that he will release his returns once the audit is complete.

Also at the rally, Sanders also slammed Trump for "recklessly" talking about the use of nuclear weapons. "Our jobs is to rid this world of nuclear weapons,” the Vermont senator said.

Also taking to the stage at the event were comedian George Lopez and "The Secret Life of the American Teenager" actress Shailene Woodley.

"Nothing is over yet and this movement is still going on strong," said Lopez, who also spoke in Spanish. "Every American deserves a better government."

Lopez continued, "You know, government is supposed to protect us citizens. Government is supposed to protect us, but somewhere along the way that stopped, it got lost. Money took over. Listen, money, I got money, it’s not everything. But I want you to have money, I want you to have education. I want you to be safe."

The former late night talk show host also took a jab at Trump, mimicking his affifnity for repeatedly telling his supporters "we're gonna win." Said Lopez, "We’re gonna win and we’re gonna win and we’re not gonna get tired of winning, we’re gonna keep winning. We’ll show you what winning looks like."

Woodley, 24, spoke about the need to be challenge the establishment.

"It’s important to remember very important to remember that our greatest defense against tyranny is our right to vote," she said. "And regardless of whether the establishment is willing to publicly admit it or not when people stand together, there’s really nothing we can’t do. You see in movements all around the world, right? They’ve been telling us for months since this campaign started that all odds are against us, but it’s not up to pundits, the media or the DNC, it’s up to us."

Sanders, meanwhile, continued to reiterate his key campaign message: "I’m running for president because together we are gonna create an economy that works for all of us not just wealthy campaign contributors," he said. "This campaign is going to win because we’re doing something very unusual in American politics. We are telling the truth. And the truth is that we have an enormous amount of greed in this country from Wall Street and corporate America. People who want it all and we’re here tonight to tell them they ain’t gonna get it all."

MaryAlice Parks contributed to this report.