On June 27, 2018, the U.S. Supreme Court struck down an Illinois law that required non-union workers to pay fees that go to collective bargaining and overturned a 1977 law that required employees to pay so-called “fair share” fees. It is believed that the ruling that could cripple public-sector unions.
See here for more information: https://www.cnn.com/2018/06/27/politics/supreme-court-union-fees-decision/index.html