Just as images emerged of 2020 Democratic candidate Pete Buttigieg dining with wealthy donors at a high-dollar weekend fundraiser, Sen. Bernie Sanders on Monday delivered a fresh indictment of a "rotten" system in which the wealthy back candidates in order to buy access and influence.

Sanders, in comments to CBS News, took a critical view of the super-rich donating large sums to political campaigns.

"Why would many, many billionaires be contributing to candidates if they didn't think they were getting something out of it?" said Sanders. "They're not doing it through the goodness of their hearts."

Buttigieg, whose campaign had already by 2019's third quarter attracted the support of 39 billionaires, came under fire from progressives on social media after pictures surfaced from a fundraiser on Sunday in Napa, California's Hall Rutherford wine caves which appeared to show the mayor dining with elites.

The Associated Press described the scene of the dinner in an article Friday:

The Hall Rutherford wine caves in the hills of California's Napa Valley boast a chandelier with 1,500 Swarovski crystals, an onyx banquet table to reflect its luminescence, and bottles of cabernet sauvignon that sell for as much as $900. It is also where Pete Buttigieg, the Democratic presidential candidate, will dine privately with donors following a Sunday fundraiser hosted by Craig and Kathryn Hall, the winery's billionaire owners, according to an invitation obtained by The Associated Press.

"Looks like a really good Black Mirror episode about the luxurious life in a billionaire's bunker as a climate apocalypse unfolds up on the surface," said Sanders speechwriter David Sirota.

Looks like a really good Black Mirror episode about the luxurious life in a billionaire’s bunker as a climate apocalypse unfolds up on the surface https://t.co/AT9P2MpvMZ — David Sirota (@davidsirota) December 16, 2019

According to Recode, a separate Buttigieg fundraiser on Monday was expected to be attended by a who's-who of Silicon Valley's powerful:

A host list circulated to prospective donors for an event on Monday morning in Palo Alto, California, features individuals with family ties to some of the most prominent people in Big Tech. Netflix CEO and co-founder Reed Hastings is listed as a co-host of the event, as is Nicole Shanahan, the wife of Google co-founder Sergey Brin; Wendy Schmidt, the wife of former Google CEO Eric Schmidt; and Michelle Sandberg, the sister of Facebook COO Sheryl Sandberg, sources say.

On Saturday, Buttigieg faced tough questions from labor reporter Mike Elk, who asked the mayor to disavow Monday fundraiser host Hastings over the CEO's support for charter schools. Buttigieg declined to do so, claiming that his positions would not be affected by big money.

Mayor Pete got testy w/ me when said that he won’t drop Netflix CEO Reed Hastings as a host from his fundraiser in Palo Alto on MondayS



Heating is a major funder of privatization & pro-voucher forces including protestors outside of the teachers union forum here in Pittsburgh pic.twitter.com/53r9P6L8Wb — Mike Elk (@MikeElk) December 14, 2019

In his comments to CBS News, Sanders expressed doubt that billionaire donors get nothing for their cash.

"I think what history tells us is that the big donors, the people who make large contributions, do get access," said Sanders. "They get tax breaks, they get deregulated. That's the way the unfortunate system is working."