Democratic presidential candidates in the party’s sixth primary debate took aim at Pete Buttigieg for his fundraisers with rich donors, lack of experience, and reluctance to embrace left-wing policies.

“Billionaires in wine caves cannot pick the next president of the United States,” said Massachusetts Sen. Elizabeth Warren on Thursday, referencing a fundraiser that Buttigieg attended in a Napa, California, wine cellar adorned with a Swarovski crystal chandelier. Warren noted she does not hold private fundraisers or “sell access” to her time.