On Monday, the U.S. Supreme Court ruled that it would not get involved in a dispute between the federal government and the Native American tribal sovereignty. In 2014, the National Labor Relations Board (NLRB) issued a ruling that made it easier for unions to organize workers employed by tribal casinos. Congress has attempted to pass a new bill that would remove the NLRB's jurisdiction over these casinos, but the bill has yet to make it through the Senate. Until this new bill is passed, the NLRB will be able to regulate labor practices that happen on Indian land.
See "Supreme Court Won't Consider Labor Board Power Over Indian Casinos", ROBERT IAFOLLA, Reuters, June 27, 2016