Some of the wealthy individuals Bernie Sanders (I., Vt.) has staked his campaign against seem to find much to like in the senator.

The latest group to endorse his presidential bid, the Sunrise Movement, is financially backed by billionaires, a wealth class Sanders wants to eliminate. The D.C.-based youth climate group on Thursday announced its support of the Vermont senator, saying he "grasps the scale of the climate crisis, the urgency with which we must act to address it, and the opportunity we have in coming together to do so."

The organization has pushed a number of controversial policies and helped craft the Green New Deal. It is also part of a coalition that met privately with Democratic presidential candidates to urge them to decriminalize border crossings and defund and reform the Immigration and Customs Enforcement agency.

The Sunrise Movement was founded in 2017 as a 501(c)(4) nonprofit that is not required to disclose its donors. However, the group's nonprofits raised nearly $1 million in 2018 with the help of the Wallace Global Fund, the foundation of billionaire and failed congressional candidate Scott Wallace, and the Rockefeller Family Fund. Inside Philanthropy reported last year that 55 percent of its funds came from institutional donors—organizations or individuals that support specific campaigns and initiatives. It pulls in 35 percent of its funds from small donors. The remaining amount comes from its nonprofit partners.

Sanders for years has attacked wealthy individuals like those who help power the Sunrise Movement as a cornerstone of his rhetoric and policy proposals, which include a wealth tax. "There should be no billionaires. We are going to tax their extreme wealth and invest in working people," Sanders said last year. "The billionaire class should be very, very nervous. The working people of this country are ready for a political revolution," he later said.

The Sunrise Movement and other prominent progressive activist groups met with Democratic presidential candidates last summer in an attempt to push them further to the left on issues like immigration.

The Sunrise Movement will host an event on Sunday with Sanders in Iowa City, Iowa, to formally announce the endorsement. The Sunrise Movement and Sanders's campaign did not return requests for comment by press time.

Sanders has been critical of Democratic challengers Joe Biden and Pete Buttigieg over their financial support from wealthy individuals.

Despite the attacks, the Vermont senator himself came under fire this week after the Associated Press raised questions over whether Our Revolution, a nonprofit established by Sanders, is skirting campaign finance laws. As a 501(c)(4) nonprofit, the group can collect unlimited amounts of money from undisclosed donors.

Our Revolution is working to increase voter turnout for Sanders's candidacy and has received nearly $1 million in contributions, including several six-figure donations. The AP noted that "groups ‘directly or indirectly established' by federal officeholders or candidates can't ‘solicit, receive, direct, transfer, or spend funds' for federal electoral activity that exceeds the ‘limitations, prohibitions, and reporting requirements' of the law." Individuals are capped at giving $2,800 per election to a campaign while political action committees are bound by $5,000 limits.