Liberal senators and Obama appointees on Wednesday decried the influence of anonymous campaign donations in American politics while citing data from organizations that accept anonymous donations.

Sen. Angus King (I., Maine) said in an opening statement before a Senate Rules Committee hearing that so-called "dark money" is a "systemic issue that threatens all of us and our very democracy." King cited data from the Center for Responsive Politics (CRP) and the Wesleyan Media Project to note that spending by groups that do not disclose their donors is nearly four times higher than it was at this time in 2012.

However, King did not mention that both of the groups have received financial support from foundations that do not disclose their donors.

CRP received $350,000 from the Open Society Foundations in 2012-13, groups that are linked to liberal mega-donor George Soros. CRP also accepted $50,000 from the Jennifer and Jonathan Allan Soros Foundation, which is named after Soros’ son.

Additionally, the Wesleyan Project has received support from the Knight Foundation, another group that is linked to the Open Society Foundations. Critics say Soros-funded groups have spent more than $50 million on efforts to influence the media and the debate surrounding campaign spending.

FEC vice chairwoman Ann Ravel was one of the witnesses at the hearing. Ravel focused her testimony on a case that arose while she was chairwoman of the California Fair Political Practices Commission (CFPPC) during the 2012 election cycle.

Ravel donated to the presidential campaigns of John Kerry, Hillary Clinton, and Barack Obama before receiving an appointment to the Obama administration’s Justice Department in 2009.

The case involved two nonprofits that failed to properly disclose independent contributions during the 2012 elections in California and were required to pay $1 million to the state. The contributions were in opposition to Proposition 30, a tax hike on the wealthy, and in support of Proposition 32, a prohibition on using union dues for political purposes.

CFPPC described one of the nonprofits, the Center to Protect Patient Rights (CPPR), as "the key nonprofit in the Koch Brothers' dark money network of nonprofit corporations." Ravel also said at a press conference in October that another one of the groups involved in the contributions, Americans for Job Security, sent money to the "Koch network" that has "tentacles all over the country."

However, Koch Industries—owned by businessmen Charles and David Koch—vigorously denied the allegations in an October statement and said they were not involved in the Proposition 32 issue.

"We did not support, either directly or indirectly, this ballot initiative which would have restricted public and private sector employees’ rights to contribute to candidates," the statement said. "The pronoun ‘we’ refers to Koch Industries and its corporate entities; Charles Koch; David Koch; and their foundations. In addition, we did not give directly or indirectly to any non-profit group in support of this ballot initiative."

Ravel was later forced to admit that the Koch brothers were not involved in the ballot initiatives. "The Koch brothers have never been implicated themselves as having been direct donors," she said.

When asked about the case after the hearing, Ravel denied being forced to "walk [her previous comments] back."

"The comment that I made was not walking that back because I never said they were related to the Kochs," she said. Her comments at the October press conference were based on testimony to the CFPPC by Tony Russo, the Republican consultant who oversaw the fundraising for the improper contributions, she said.

However, Russo never explicitly linked the contributions to the "Koch network" in his testimony. Russo worked with GOP strategist and former Koch consultant Sean Noble—also head of CPPR—to funnel the contributions through the nonprofits, but he said he "assumed CPPR was part of the Koch [network]."

"We didn’t really do any research on Noble but he came highly recommended by donors," Russo said. "You know, some of the donors in our network are also members of the Koch network."

Koch has repeatedly said that they had no involvement whatsoever in either California ballot initiative and that they did not know Noble was helping Russo at the time.

Sen. Pat Roberts (R., Kansas), ranking member on the Senate Rules Committee, asked Ravel during the hearing about an FEC attorney who recently resigned after sending "dozens of partisan political tweets" including solicitations for contributions to President Obama’s 2012 campaign.

Ravel said there is "no reason to believe that this is extensive or goes beyond anybody other than this individual who has since been terminated."

"In my six months at the FEC I have never heard any partisan communications by either employees or commissioners," she said.

Roberts responded with surprise.

"That must be one agency that is an island in the sun," he said.

Wednesday’s hearing also came amid the annual meeting for the secretive club of wealthy liberals known as the Democracy Alliance, which has steered more than $500 million to liberal groups since its inception in 2005.

One of its members, hedge fund billionaire Tom Steyer, has pledged to spend $100 million on candidates in the midterm elections who say they support environmentalist causes—but recently said he will not disclose the donors.

Neither the alliance nor Steyer were discussed at the hearing.