Sen. Elizabeth Warren traded jabs with Mayor Pete Buttigieg over campaign finance at this week's Democratic presidential debate.

Warren zeroed in on Buttigieg courting of wealthy donors, in part through private fundraisers like a one held in a California "wine cave."

However, Warren has a lengthy track record of courting wealthy donors, including at events like a wine fundraiser held in Boston in June 2018.

Visit Business Insider's homepage for more stories.

WASHINGTON (AP) — On a Saturday evening in June 2018, with temperatures in the 70s and the Red Sox playing at Fenway Park, supporters of Massachusetts Sen. Elizabeth Warren gathered at the City Winery Boston for a fundraiser.

They were treated to songs by the Grammy-winning artist Melissa Etheridge and heard remarks from Warren, who was months away from announcing her campaign for the 2020 Democratic presidential nomination. For the top donors, those who could contribute or raise $5,400 per couple or $2,700 a person, there was a VIP photo reception and premium seating.

For them and others who gave at least $1,000, there was also a gift: a souvenir wine bottle.

In Thursday night's Democratic presidential debate in Los Angeles, rival Pete Buttigieg, the mayor of South Bend, Indiana, for attending a fundraiser at a "wine cave" in California's where he under a chandelier with Swarovski crystals and where bottles of cabernet can sell for $900.

"Billionaires in wine caves should not pick the next president of the United States," Warren said. Later, she added, "I do not sell access to my time."

Democratic presidential hopefuls (fromL) yan, Mayor of South Bend, Indiana Pete Buttigieg, Massachusetts Senator Elizabeth Warren, former Vice President Joe Biden and Vermont Senator Bernie Sanders arrive onstage ahead of the sixth Democratic primary debate of the 2020 presidential campaign season co-hosted by PBS NewsHour & Politico at Loyola Marymount University in Los Angeles, California on December 19, 2019. ROBYN BECK/AFP via Getty Images

Vermont Sen. Bernie Sanders joined in, attacking Buttigieg for consorting with millionaires and billionaires. Even Andrew Yang, the entrepreneur who rarely criticizes his fellow candidates, added to the chorus when he ridiculed the idea of politicians who "go shake the money tree in the wine cave." Minnesota Sen. Amy Klobuchar tried to make light of it all when she said that while she had never been to a wine cave, she had visited "the wind cave in South Dakota."

The term #Winecave trended on Twitter.

As a White House contender, Warren has made a conversion to spurn big-dollar donor events like the one in Boston. It's an effort to burnish her appeal as a can't-be-bought candidate with deep grassroots support, a point of pride she used to bludgeon Buttigieg.

But some see her transition from a prolific force on the donor circuit to a presidential hopeful who has tried to curb others from doing much the same as less than noble.

"Challenge Pete on everything from his age and experience to his record in South Bend," said Rufus Gifford, former finance director for President Barack Obama's campaign. "I think that's totally fair. But this is just disingenuous. It implies a level of corruption and cronyism that is inaccurate and ultimately plays into the hands of Republicans."

Warren and Sanders have made scorning the big money part of a broader campaign to rid what they say is its corrupting influence in politics.

For Sanders, that's been his practice for decades. For Warren, as the Boston event shows, it's come more recently. She used more than $10 million from her Senate campaign account, some of it raised at large donor events, to help seed her presidential bid, a fact Buttigieg eagerly pointed out.

Past Warren donors say she was an engaging presence at those events, asking questions of her wealthy patrons and listening intently to what they had to say.

She also made it personal. She bestowed awards on those who were successful at tapping their personal networks to raise money for her. Those who bundled large amounts under $50,000 for her Senate campaign earned a silver pin, while those who brought in more were awarded a gold one engraved with her signature. Her campaign says it's a practice she discontinued long ago.

Despite a pledge not to hold private fundraisers, Warren has held gatherings similar to those she's criticized others for.

Sen. Elizabeth Warren (D-MA) greets members of the audience after the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Justin Sullivan/Getty Images

As Warren considered a White House run, she held a series of small meetings at her home to court top Boston-area donors who raised larges sums for Hillary Clinton and to gauge their interest in supporting the senator's potential bid, according to a past contributor who attended one of the meetings. The donor spoke on condition of anonymity to discuss private matters.

"When we made the decision to run the campaign this way, the players in the usual money-for-influence game dismissed it as naive," Warren spokesman Chris Hayden said in a statement. "We're pleased that our 100% grassroots strategy has been so effective that they're now threatened enough to be attacking us for it."

Even after her pledge not to hold private fundraisers, Warren has continued to attend the very kind of events for which she has criticized others. She has headlined fundraisers for the Democratic National Committee in settings that raise handsome sums, and she said he would continue to do that if she were the nominee, so that Democrats would not be at a financial disadvantage against President Donald Trump.

Those kind of events are at odds with her self-proclaimed image of a candidate who would rather be taking down-to-earth selfies with supporters who send her campaign $5 rather than being among the party's donor elite.

It's a practice that she's also followed in her home state.

Alix Ritchie, who has donated more than $20,000 to Warren, said she had co-hosted events and attended others. "Many of the events for her that I went to were on the Cape in the summer," said Ritchie, formerly the publisher of the Provincetown Banner newspaper. "They would have wine and some kind of finger food. It's pretty standard. It wasn't any different from what other people do. She raised money the way every candidate raises money."

Warren has also attended fundraisers on Manhattan's Upper East Side and in Greenwich Village and at a mansion in Santa Monica, California. The events brought in hundreds of thousands of dollars for her Senate campaigns and other Democratic causes.

Warren has a long-held network of wealthy donors

Famous names sponsored fundraisers for Warren, too. Among them: actors Matt Damon and Ben Affleck, as well as well-known Democratic donors such as financier George Soros.

In 2012, she attended a New York fundraiser hosted by the same donor, Kevin Ryan, who put on a Buttigieg event this month that drew protesters who support her as well as Sanders

But just because Warren no longer attends big-dollar events or offers some of the same perks that she used to doesn't mean she's entirely sworn off taking money from wealthy donors who tap their networks to raise large sums.

Her campaign allows her wealthy supporters to establish pages on the Democratic fundraising site ActBlue. The roster reads like a who's who of wealthy progressives.

They include Vin Ryan, the founder of Schooner Capital with net worth estimated to be greater than $500 million; Stephen Silberstein, a wealthy Bay Area tech company founder; and Ian Simmons, the founder of the investment group Blue Haven Initiative, who married into the Pritzker family that operates the Hyatt Hotel chain.

Warren's campaign says that anyone is free to set up such a page. The senator, they add, does not attend any of the events the donors hold and no longer offers special perks.

"I've said to anyone who wants to donate to me, 'If you want to donate to me, that's fine, but don't come around later expecting to be named ambassador,' because that's what goes on in these high-dollar fundraisers," Warren said during this week's debate.