WASHINGTON, Dec. 17 (UPI) -- Sen. Bernie Sanders, I-Vt., picked up a major endorsement from the Communication Workers of America, his most powerful union endorsement so far.
The announcement came at a press conference at the union's headquarters in Washington, D.C., on Thursday.
Sanders has been passed up for significant union support in favor of Hillary Clinton, who now boasts the support of unions representing about 12 million Americans, including the Service Employees International Union (SEIU) and the American Federation of State, County and Municipal Employees (AFSCME).
CWA says it has more than 300,000 active and retired members in states with primaries and caucuses coming up before April 1. The union represents roughly a half a million workers nationwide.
Politico reported CWA's endorsement is the third national union endorsement for Sanders. He nabbed endorsements from National Nurses United in August and the American Postal Workers Union in November. All three unions combined represent about one million workers.
NBC reported Larry Cohen, the former president of CWA, joined Sanders' campaign as a top labor adviser in June.
The union said previously that its members would decide which candidate to endorse through an online poll, much like how the Working Families Party chose Sanders as their nominee earlier this month.