An unexpected burst of plain speaking recently swerved the race for the Democratic presidential nomination off the customary narrative. Howard Dean, the former head of the Democratic National Committee and candidate for the party's 2004 nomination, not only admitted but asserted that labor unions are super PACs.

While on the campaign trail, Dean — a Hillary Clinton supporter — described unions as super PACs while attempting to counter suggestions that Clinton was beholden to Wall Street, after collecting significant sums for speeches at financial industry events.

“Why does Hillary Clinton have to put up with a double standard?” Dean asked. “I don’t hear anybody asking Bernie Sanders for his transcripts for some speech he made with a labor union. Frankly, for Bernie to say he doesn’t have a super PAC. ... Labor unions are super PACs. Now, they’re super PACs that Democrats like, so we don’t go after labor unions, but this is a double standard.”

A PAC, or political action committee, pools contributions and can both give money directly to candidates and pay for independent political activities on a candidate’s behalf. A major difference between a PAC and a super PAC is that there is no cap on how much money can be contributed to a super PAC. Also, super PACs are not allowed to contribute directly to or coordinate with election campaigns.

“It seems like everyone tends to think of super PACs as being something primarily associated with the far right,” said Dennis Darnoi, a political consultant with RevSix Data Systems. “They see super PACs as being funding from the Koch brothers and sources like that. Without ever looking closely at political funding issues for themselves, most people probably equate super PACs with conservative candidates and issues. I think that’s largely due to the way things are generally reported by the news media.”

Bill Ballenger, founder of Inside Michigan Politics, agreed that there seems to be a distinction between reality and perception on campaign spending.

“Aside from stories about George Soros, who contributes heavily to the Democrats, the Republicans have been perennially characterized as the ones who are always financially supported by rich contributors and corporate interests,” Ballenger said. “This fits in well with the class warfare rhetoric the Democrats always end up relying on. And, although Democrats certainly get their share of funding from well-financed sources — including unions — the Republicans almost never say or do anything to try to contradict the general perception.”

“So — yes, it’s kind of interesting that Dean would say something like he did about the unions,” Ballenger continued. “But what’s even more intriguing to me is that Dean and Sanders are both from Vermont, which makes me wonder what might have happened between them in the past that would cause Dean to go after Sanders so aggressively.”

Seven of the top eleven organizations that spend the most on political campaigns in the U.S. are labor unions, according to the Center for Responsive Politics. The Service Employees International Union, which has contributed over $224 millions during recent campaign cycles, ranks No. 1. 

The top 100 political donors of 2014 gave roughly $174 million to Democrats and $140 million to Republicans, according to a POLITICO analysis of data from the Federal Election Commission and Internal Revenue Service.

Bob Allison, the executive director of the SEIU Michigan State Council, did not respond to an email offering him the opportunity to comment. Doug Pratt, the director of public affairs for the Michigan Education Association, did not return a phone call offering him the opportunity to comment.