Leading congressional Democrats on Tuesday said democracy was under threat from the Koch brothers at a screening of a new film critical of the powerful political duo.

A seven-minute clip of the film, “Koch Brothers Exposed,” was shown at the event, held at the Congressional Visitors Center. Film director Robert Greenwald, the president of Brave New Films, which produced the film, said it was inspired by Jane Mayer’s critical article on the Kochs in the New Yorker.

“What (the Koch brothers) do with their money isn’t fine with me,” declared Senate Majority Harry Reid in one clip in the documentary. He added that the Kochs want to “do away with government.”

The film takes aim at the father of the Koch brothers, suggesting he was a racist and also profited from dealings with the Soviets.

"If the Koch brothers can buy the Senate, what's next -- gonna buy a president?" Reid said at the end of the clip.

After the clip of the film was shown, Reid addressed the attendees.

“We’re here because they’re trying to buy our democracy,” said Reid, a frequent critic of the Koch brothers. "But they can't shut down free speech, though the Supreme Court has done a good job of it.”

House Minority Leader Nancy Pelosi added, “Our founders wanted a democracy, a government of the many -- not of the money." 

“People know these are not people who share their values about safety in our economy and fairness. They have an agenda," she said.

The screening triggered criticism from Republicans, who said it constituted a political event on congressional property, which is forbidden. A spokesman for Pelosi, however, claimed in a statement Monday that the event is not a premiere or a screening, but rather a press conference where clips from the film would be shown.

Through the Super PAC they helped found, Americans for Prosperity, the brothers are blanketing key 2014 battleground states with a $30 million ad blitz aimed at Democratic candidates who voted for ObamaCare.

Fox News’ Kara Rowland contributed to this report.