The U.S. Supreme Court appears poised to strike down most of the remaining limits on massive spending by wealthy donors on political campaigns. On Tuesday, justices heard arguments in McCutcheon v. Federal Election Commission, which has been referred to as “the next Citizens United.” Republican leaders and wealthy GOP donor Shaun McCutcheon want the Supreme Court to throw out aggregate limits on individual contributions in a single two-year cycle, saying they violate free speech. On Tuesday, the likely swing vote, Chief Justice John Roberts, indicated he is prepared to strike down caps on donations to individual candidates, but perhaps not on donations to political committees. At a rally outside the hearing, Senator Bernie Sanders said unlimited private spending undermines U.S. democracy.

Sen. Bernie Sanders: “The bottom line here is that if we do not want to move this nation to an oligarchic form of society, where a handful of billionaires can determine the outcome of these elections, then it is imperative not only that we overturn Citizens United, but that we put a lid on how much people can contribute in elections. Freedom of speech, in my view, does not mean the freedom to buy the United States government.”

The McCutcheon case marks the first major challenge to campaign finance rules since the 2010 Citizens United decision, which opened the floodgates for unlimited corporate spending on elections.