Bernie Sanders says often he does not want or need a super PAC to back him, and he has no interest in spending his time at exclusive fundraisers, persuading wealthy people to write checks for his campaign. But the untidy reality of running for president in 2015 has sometimes failed the exacting Vermont senator’s standards.

Since starting his campaign, one super PAC supporting Sanders has spent hundreds of thousands of dollars, and a second has endorsed him. Separately, Sanders has hosted at least nine medium- to high-dollar, closed-door fundraisers in New York, Los Angeles and elsewhere to directly fund his own presidential campaign. Even though Sanders’ efforts sometimes have a proletarian flair—he held one $200-per-ticket fundraiser at a dive bar near a grungy Seattle park—some aspects of the Democratic insurgent’s fundraising are similar to the candidates he condemns.

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Sanders has also benefitted from the financial support of a national nurses union’s super PAC. The executive council of the 185,000-member National Nurses United voted to endorse Sanders in August, becoming the first major national union to support Sanders. Since then, the union’s super PAC arm, National Nurses United for Patient Protection, has spent more than $610,000 on billboards and web advertising supporting Sanders, according to an analysis of FEC records.

National Nurses United has paid for several variations of billboards in Iowa, one of which features a photo of a nurse and a child and touts Sanders’ Medicare-for-all proposal which would cost trillions but guarantee healthcare to all Americans. “Politics as Usual Won’t Guarantee Healthcare For All. Bernie Will,” says the billboard. Another shows a collapsed bridge next to the words “Politics as Usual Won’t Rebuild America. Bernie Will”—a reference to Sanders’ proposed $1-trillion infrastructure program.

Union representatives say that the nurses’ super PAC’s funding, which comes exclusively from its own union members’ dues, is different from other super PACs that depend on a handful of ultra-rich contributors. “A PAC that enables the union to use resources for someone who is 100% with them is a very easy thing to do, and there is no concern over the vehicle for doing it,” said Michael Lighty, director of public policy for National Nurses United. “The union doesn’t even really believe it is a super PAC.”

Sanders has not encouraged any spending or fundraising with National Nurse United’s super PAC. The average donation to his campaign is around $30, and Sanders has collected contributions from at least 800,000 individual people. He has more small-dollar contributors at this point in his campaign than any presidential primary candidate in recent history, including then-Sen. Barack Obama in 2007. Sanders’ campaign has generally denounced super PAC spending, but has not specifically called on the nurses’ union to cut off their support.

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“We have by far the most transparent fundraising of anyone in this campaign,” said Sanders’ campaign manager, Jeff Weaver. “Yes, there’s this or that event, but the question eventually is, ‘where is all your money coming from?’ The important thing is what percentage of Bernie’s money comes from contributions under $200. It’s almost all of it.”

A second super PAC, Progressive Kick, has endorsed Sanders but has not yet committed to spending money to support him. Progressive Kick spent about $2 million in races to support liberal Democrats in races across the country during the 2014 cycle and raised large funds from a couple of major donors. One of the largest donors to Progressive Kick was none other than National Nurses United, which donated nearly $2 million in 2014. Other donors spent upwards of $50,000 for the super PAC, according to records.

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Progressive Kick President Joshua Grossman said that if his super PAC supported Sanders, it would use a separate fundraising mechanism to only spend money raised from small donors. But the Sanders campaign already raises money itself from small donors, due in part to fundraising restrictions. “We’re very nimble and we’ll engage in different fundraising strategies and campaign techniques,” Grossman said, explaining why any funding for Sanders would not be redundant considering the campaign’s spending. “We have pretty brilliant campaign techniques that are ahead of the ‘madding crowd,’ so to speak.”

After the 2010 Citizens United Supreme Court decision that enabled super PACs, a politician who seeks absolute purity can be drawn into uncertain waters. Sanders cannot prevent a super PAC from spending money to support him, as they technically act independently of candidate’s campaign, but there is a long tradition of candidates stopping such spending with public denunciations.

Sanders’ own high-end campaign fundraisers can be both rarefied and homier affairs. Mark Ruffalo, the actor who played the Incredible Hulk, spoke at a Sanders fundraiser in September in New York. So did a local union leader. In October, Sanders went to a fundraiser in Beverly Hills, California hosted by real estate agent Syd Leibovitch. Attendees, some dressed in blazers and cocktail dresses and others in polo shirts and jeans, had valet parking and drank an assortment of wines. The minimum donation for entry was $250, and some donors gave up to $2,700. The event raised $150,000, the campaign estimated.

“$2,700 is something most people can’t even thinking about, but it’s not ‘buying a candidate,’” said Mimi Kennedy, an actress who attended the October fundraiser for Sanders and hosted her own in June. “People who like Bernie are smart and political savvy enough to know that money is part of the race.”

Sanders is competing against the well-funded and establishment-backed Clinton, who regularly attends high-dollar fundraisers with a minimum entry ticket of $2,700 donation. Clinton headlined nearly 60 fundraisers in July, August and September of this year, raising upwards of $400,000 at some of the events, according to the Clinton campaign. “Sanders is doing a great job raising money from small donors,” said Daniel Weiner, senior counsel at the Brennan Center, “but it’s going to be hard to sustain his campaign with just that if he is going to be able to compete with Hillary Clinton.”

Clinton’s main campaign super PAC, Priorities USA Action, is bankrolled by wealthy donors like investor George Soros, Hollywood director Steven Spielberg and others, many of whom can be counted on to contribute $1 million checks. Clinton has embraced the super PAC, and her campaign chair John Podesta appeared at a Priorities event in September. Priorities is planning to spend many millions against Republicans, assuming Clinton makes it to the general election.

But so far Priorities USA has only spent $280,000 supporting Clinton in the primary, according to records—less than half as much as the more than $600,000 National Nurses United has spent to support Sanders. Clinton has also condemned super PACs, but said she would use one in order to beat the Republicans. “I and others have said we’re not going to unilaterally disarm while the Republicans and the Koch brothers are out there raising money that they don’t even tell you where it came from,” she said at a campaign event in Mount Vernon, Iowa in October.

In a similar vein, Sanders also has a presidential campaign to run. “The truth is there are many people in this country who have money but also believe in social justice,” Sanders told the crowd at the Beverly Hills fundraiser.

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