California workers at Kaiser Permanente have voted to remain represented by the Service Employees International Union-United Healthcare Workers West. SEIU-UHW said that it won about 58% of the vote against the National Union of Healthcare Workers, a smaller union looking to represent the workers. The union had won another election in 2010, but the victory was thrown out by the National Labor Relations Board because of threats made against workers.
See "SEIU wins union vote from Kaiser workers, defeating smaller rival", Chad Terhune, Los Angeles Times, May 2, 2013