The Supreme Court opened a new term Monday, hearing arguments in a case that could expand the rights of millions of workers to sue their employers. The case, NLRB v. Murphy Oil, pits workers who want the right to join class action lawsuits against employers—backed by the Trump administration—who want to force workers to enter into binding arbitration agreements that prohibit collective litigation. The Economic Policy Institute says more than half of all non-union U.S. workers are currently forced to work under mandatory arbitration rules.