Multiple Democrats sparred over the use of closed-door, high-dollar “wine cave” fundraisers to make money at the sixth Democrat debate in Los Angeles, California, at Loyola Marymount University Thursday night.

Sen. Elizabeth Warren (D-MA) slammed South Bend, Indiana, Mayor Pete Buttigieg for his recent “wine cave” fundraiser in Napa Valley, California, to get money from more high-dollar donors.

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

Buttigieg responded that he is the only candidate onstage “who is not a millionaire or a billionaire,” dismissing criticism of his rubbing shoulders with the upper class.

“You know, according to Forbes magazine, I’m literally the only person on this stage who is not a millionaire or a billionaire. So this is important,” Buttigieg said. “This is the problem with issuing purity tests you cannot yourself pass.”

The exchange soon turned into a purity test over how many big-ticket fundraisers each candidate has held.

Later in the debate, Sen. Amy Klobuchar (D-MN) interjected, saying, “I did not come here to listen to this argument.”

“I came here to make a case for progress, and I have never been to a wine cave,” she said, admitting that she had been to a wind cave in South Dakota.

A “wine cave” is a “subterranean structure” made for “storing and aging wine,” according to the wine glossary at winerytouringsandtastings.org.

Many of these wine caves are located in Sonoma and Napa Valley, California, where Buttigieg held his fundraiser at an opulent winery. Tickets were $500 apiece, and attendees could fork over $2,800 a head to dine with the South Bend, Indiana, mayor.