On Tuesday, legislation was passed by the U.S. House of Representatives that would prevent the National Labor Relations Board from having jurisdiction over casinos that are located on Native American Reservations. The White House has directly spoken out against this piece of legislation, but made no indication that it would be vetoed. If this bill is approved, it would make it very difficult for employees to unionize at these casinos. Given the pushback, it is unclear whether this bill will become a law.
See "Bill to Shield Tribal Casinos From Labor Board Clears the U.S. House", November 18, 2015