Sen. Bernie Sanders and Rep. Alexandria Ocasio-Cortez slapped South Bend Mayor Pete Buttigieg for holding fancy fundraisers with rich donors during a Venice Beach rally on Saturday.

'We don't go to rich people's wine caves,' Sanders told a crowd of thousands gathered between the Venice Beach boardwalk and the Pacific Ocean. Sanders was referring to a Napa Valley Buttigieg fundraiser that cost $900 to attend.

Ocasio-Cortez's attack was more subtle, as she explained why she was OK with there being 'purity tests,' a line Buttigieg used at Thursday's Los Angeles debate, as he complained that he was the only candidate onstage who wasn't a millionaire or more, and needed all the help he could get with money to sustain a campaign.

'Anyone who accuses us of instituting purity tests, it's called having values, it's called giving a damn,' Ocasio-Cortez said.

'Let me tell you something,' the freshman Democratic congresswoman from New York went on. 'I go to work all the time and I hear people say, "what will my donors think?" I hear that phrase. And I hear and I see that billionaires get members of Congress on speed dial and waitresses don't.'

Vermont Sen. Bernie Sanders called out Mayor Pete Buttigieg without uttering his name by telling a crowd of supporters Saturday at Venice Beach that 'We don't go to rich people's wine caves'

Rep. Alexandria Ocasio-Cortez gave South Bend Mayor Pete Buttigieg a subtle slap by explaining that the Democrats need 'purity tests' because she's watched her fellow members of Congress respond to billionaires' calls - but not those from waitresses

Sen. Bernie Sanders (left) joined hands with Rep. Alexandria Ocasio-Cortez (right) after she spoke Saturday at a Venice Beach rally in California

Sen. Bernie Sanders (left) praised freshman Democratic Rep. Alexandria Ocasio-Cortez (right) during their first west coast rally together since her October endorsement

Large signs for 'Bernie' and 'AOC' are seen in the background of Sen. Bernie Sanders' Venice Beach rally Saturday, which also featured Rep. Alexandria Ocasio-Cortez

The campaign told DailyMail.com that 14,147 attended Sen. Bernie Sanders rally Saturday in Venice Beach in Los Angeles, California

Sen. Bernie Sanders is seen onstage, with wife Jane Sanders seated nearby, Saturday during the 2020 hopeful's campaign rally on Venice Beach

Bernie Sanders supporters cheer for their candidate at the Vermont senator's presidential campaign rally Saturday in California

An American flag and the California state flag were on full display at Saturday's Bernie Sanders rally on Venice Beach in Los Angeles, California

Rep. Alexandria Ocasio-Cortez (left) endorsed Sen. Bernie Sanders (right) in October and appeared with him Saturday in Los Angeles. They'll also campaign together in Las Vegas on Sunday

Ocasio-Cortez worked as a bartender before being elected to Congress last year.

Sanders and fellow progressive Sen. Elizabeth Warren have sworn off getting help from Super PACs. They have raised campaign cash using small dollar donations. Buttigieg has participated in glitzy closed-door fundraisers, though has released the names of most of his bundlers. Transparency, though, hasn't been enough for him to avoid attacks from the Sanders-Warren wing.

It was Warren who brought up the $2,800 a head wine cave Buttigieg fundraiser at Thursday's Democratic debate.

'Think about who comes to that,' Warren said. 'We made the decision many years ago that rich people in smoke-filled rooms would not pick the next president of the United States. Billionaires in wine caves should not pick the next president of the United States.'

Buttigieg suggested those candidates should look in the mirror.

'According to Forbes magazine, I am ... the only person on this stage who's not a millionaire or a billionaire,' Buttigieg said. 'This is the problem issuing purity tests you yourself cannot pass.'

Ocasio-Cortez's dig came after she had gone after Congress for passing President Trump's bloated defense budget. Trump signed it into law Friday at Joint Base Andrews before leaving to spend the holidays at Mar-a-Lago. The bill includes Trump's new Space Force.

South Bend Mayor Pete Buttigieg has been attacked by his more progressive rivals for holding a high-dollar fundraiser in this Napa Valley wine cave

A look at the wine cave used for a Pete Buttigieg fundraiser that became one of the most memorable phrases during Thursday night's Democratic primary debate in Los Angeles

Ocasio-Cortez said she was asked 'not once' whose taxes would go up to pay for President Trump's $738 billion Defense budget. 'This is not just some kind of campaign line,' she said.

'We only talk about raising taxes when it comes to taking care of our kids and saving our planet and establishing healthcare - it is the ultimate hypocrisy,' Ocasio-Cortez told the crowd.

Ocasio-Cortez, dressed in a bright red dress, tossed out some red meat for the liberal crowd of 14,147 people, according to the Sanders campaign.

'We need to dismantle ICE and CBP,' she said at one point.

When one attendee started yelling about fascism, Ocasio-Cortez paused her speech to agree.

'It is fascism, what we're evolving into,' she commented. 'I'm sorry, I'm a little thrown off here,' she said, as the person screaming had gotten her off the beat of her speech

The beachfront rally also featured a surprise appearance from actor Tim Robbins, who supported Sanders in 2016, and was already on board with the 2020 campaign, but made his endorsement official.

'I'm endorsing Bernie Sanders today because I believe he will lead this country with a spirit of inclusiveness and in the service of the people he represents, not the money that got him there,' Robbins told the crowd.

Robbins noted that 'the president is not a king.'

'He works for us,' the actor said.

Sen. Bernie Sanders hosted a Saturday rally in Venice Beach that featured Rep. Alexandria Ocasio-Cortez, actor Tim Robbins and Dr. Cornell West

Actor Tim Robbins, a longtime Sanders supported, surprised the crowd with his appearance and made his 2020 endorsement official

A Bernie Sanders supporter shows off a campaign sign at the site of the Vermont senator's Venice Beach rally Saturday

A poster advertising Bernie Sanders' rally with Rep. Alexandria Ocasio-Cortez

A supporter holds up a sign with Bernie Sanders' campaign slogan 'Not Me, Us,' with a drawing of Rep. Alexandria Ocasio-Cortez

A cardboard cut-out of AOC is used to model merchandise for Bernie Sanders' California rally with the Democratic congresswoman

Bernie Sanders shirts in the colors of the rainbow were being sold outside his Venice Beach rally site Saturday

Tables of Bernie Sanders merchandise lined the Venice Beach boardwalk, right outside where Sanders held a rally with Rep. Alexandria Ocasio-Cortez

'Bernie has always governed that way,' he continued. 'He's what my grandmother used to call the "geniune article."'

Ocasio-Cortez was introduced by Dr. Cornell West.

Three music acts - Young the Giant, Local Natives and Jesse & Joy - performed at the oceanfront rally.

With California Sen. Kamala Harris out of the presidential race, Sanders is currently leading the pack to pick up the delegate-rich state.

A Change Research poll conducted for KQED earlier this month found that 26 percent of Californians supported Sanders, followed by Sen. Elizabeth Warren at 23 percent and former Vice President Joe Biden at 19 percent. South Bend, Indiana Mayor Pete Buttigieg is next with 12 percent. And Andrew Yang clocks in at 4 percent.

In the last cycle, California was Sanders' last hope to beat Hillary Clinton, as the state's primary was in June, at the very end of the cycle.

This year Californians will vote much sooner, as the state's primary is scheduled for March 3 - what in politics is dubbed 'Super Tuesday' - as voters from 14 states and American Somoa will head to the polls or caucus sites.

Ocasio-Cortez announced that she still felt the Bern on October 15, the night Sanders debated his Democratic rivals in Ohio - his first event after recovering from a heart attack. She had supported his 2016 campaign.

She made her endorsement official at a rally in their native New York City.

The congresswoman has campaigned alongside Sanders in Iowa as well.

After her Venice Beach appearance she'll travel with Sanders to Las Vegas to keynote a Spanish-language town hall on Sunday.

Besides Ocasio-Cortez, Sanders has attracted the endorsements of two other members of the so-called 'squad' - Reps. Ilhan Omar and Rashida Tlaib.

They've made campaign appearances with Sanders in their home states of Minnesota and Michigan.