The Communications Workers of America will endorse Bernie Sanders in Washington on Thursday, according to a source with knowledge of the endorsement.
Despite a long record of supporting unions and marching on picket lines, Sanders has struggled to lock down national union endorsements. With 700,000 members, the Communications Workers of America is the largest union to endorse the Vermont senator.
The endorsement is not surprising: Larry Cohen, the union’s former president, joined the campaign is June and is now the campaign’s top adviser on labor issues.
After not endorsing in the 2008 nomination fight, the union announced in August that it had set a process in motion to determine whether its members wanted to get involved in the Democratic primary and who they would want to endorse.
The union provided members with an online poll in September and used the results were used to determine their endorsement.
“CWA has not made an endorsement for the presidential primary elections,” Chris Shelton, president of the union, said in August. “CWA doesn’t get out in front of our members, and our members will decide what action we take on endorsement.”
Hillary Clinton, the Democratic front-runner and Sanders’ top opponent, has so far had a tight grip on union support, racking up 18 national union endorsements since announcing her campaign earlier this year.