Nearly one in 10 superdelegates who voted in the Democratic presidential primaries were registered lobbyists, according to a new report, adding some support to Bernie Sanders's claim that "the system is rigged."

At least 63 of 712 superdelegates were registered at some point as lobbyists on the state or federal level, according to an analysis conducted this year by the nonpartisan, nonprofit Sunlight Foundation.

These individuals represented interests that span across big banks, healthcare insurers, the telecommunications industry and unions, including Goldman Sachs and Planned Parenthood.

The list includes former Senate Majority Leader Tom Daschle, who is currently registered for the healthcare insurance company Aetna, former House Minority Leader Richard Gephardt, a registered lobbyist with the Gephardt Group and former DNC General Chairman and Pennsylvania Gov. Ed Rendell, who was registered for Ballard Spahr LLP as recently as 2012.

Sunlight also found an additional 32 individuals it classified as "shadow lobbyists," which it says are superdelegates who "aren't officially registered as lobbyists, but are heavily involved in the influence industry."

This group includes the likes of former Vermont Gov. and DNC Chairman Howard Dean, who is a "senior adviser" for Dentons, a law firm.

While the rules surrounding superdelegates for the next presidential primary will see some changes — with Democrats agreeing to significantly reduce the number of superdelegates not bound by primary voters — critics of superdelegate system have complained that it put the establishment in a position to throw the 2016 Democratic nomination into Hillary Clinton's lap.

More than 600 superdelegates backed the former secretary of state, and in some cases handed her more delegates than Sanders in states where he won a majority of the primary vote. A total of 2,383 delegates were needed to clinch the nomination.

Much of Sanders' 14-month progressive campaign to become the Democratic Party's nominee was spent railing against a political system in which the wealthy and special interests determine the result of the election.

"In the year 2016, with a political campaign finance system that is corrupt and increasingly controlled by billionaires and special interests, I fear very much that, in fact, government of the people, by the people, and for the people is beginning to perish in the United States of America," Sanders said.

The findings of the Sunlight Foundation also show that despite a common refrain from Democrats that Republicans are controlled by lobbyists and special interests, such as the National Rifle Association, when it comes to delegates who are unaccountable to voters, the opposite is true. While the Republican Party does have its own version of superdelegates, they must vote for the candidate that their state's party members picked.

To view the Sunlight Foundation's entire list of lobbyist superdelegates, click here.