Sen. Bernie SandersBernard (Bernie) SandersModerates see vindication in Lipinski’s primary win Sanders: Fox News 'couldn't handle' town hall on economic inequality Mississippi woman appointed to Senate, making Vermont only state to never have female lawmaker MORE (I-Vt.) said Wednesday that billionaires are trying to turn the United States into an oligarchy by influencing elections and policy with their money.

“I do not believe democracy is about a handful of billionaires, such as the Koch brothers and Sheldon Adelson, being in a position where they can spend as much money as they want on any political race in this country,” Sanders said. “That’s not democracy … it is oligarchy.”

Sanders's comment came after the Supreme Court recently ruled that caps on election contributions are unconstitutional. That ruling allows unlimited amounts of money to flow directly into the U.S. political system.

Sanders said wealth inequality is a core issue and the reason the middle class is shrinking in the United States. He said billionaires like David and Charles Koch and Sheldon Adelson are using their money to ensure federal laws allow them to make more and more money at the expense of the working class.

The Kochs, billionaire oil tycoons, and Adelson, a casino magnate, have contributed millions to Republican campaigns through political action committees and are expected to give even more now that there are no direct contribution caps.

Democrats have attacked those wealthy donors in recent months, trying to tarnish their image ahead of November’s midterm election.

Republicans argue campaign contributions are a form of free speech and should not be limited.