Los Angeles CNN  — 

The term “wine cave” was thrown around repeatedly Thursday night at the Democratic presidential debate during an exchange over how Pete Buttigieg is funding his campaign.

Here’s why: The South Bend, Indiana, mayor headlined a fundraiser earlier this month in Rutherford, California, at Hall Wines, a winery owned by Kathryn Hall, who was the US ambassador to Austria from 1998 to 2001, and her husband, Craig.

Part of the event took place in a so-called “wine cave” under a chandelier of 1,500 Swarovski crystals.

Photos were posted online of Buttigieg sitting beneath the chandelier, leading to him being roundly mocked for the event and adding to the criticism he has taken for headlining top-dollar fundraisers.

“So the mayor just recently had a fundraiser that was held in a wine cave full of crystals and served $900-a-bottle wine,” Sen. Elizabeth Warren of Massachusetts said on Thursday.

She later said, “Billionaires in wine caves should not pick the next president of the United States.”

After a long back-and-forth between Warren and Buttigieg, Sen. Amy Klobuchar of Minnesota said, “I did not come here to listen to this argument. I came here to make a case for progress. And I have never even been to a wine cave.”

Entrepreneur Andrew Yang, in a bid to tout his Democracy Dollars campaign fundraising plan, which would give Americans money to contribute to political candidates, said, “If we were to put 100 Democracy Dollars into the hands of every American voter, instead of 5% contributes, you’d see the rates skyrockets and you would have many, many more women that would run for office because they don’t have to shake the money tree in the wine cave.”

Buttigieg defended his fundraising by saying, “We’re in the fight of our lives right now. Donald Trump and his allies have made it abundantly clear that they will stop at nothing, not even foreign interference, to hold on to power. They have already put together more than $300 million. This is our chance.”