Story highlights The union has 12 million members

It endorsed Clinton on Thursday

(CNN) The leadership of the AFL-CIO voted on Thursday to endorse Hillary Clinton for president, according to a spokesman for the union federation.

"Hillary Clinton is a proven leader who shares our values," AFL-CIO President Richard Trumka said in a statement after the vote. "Throughout the campaign, she has demonstrated a strong commitment to the issues that matter to working people, and our members have taken notice. The activism of working people has already been a major force in this election and is now poised to elect Hillary Clinton and move America forward."

The endorsement from the more than 12 million member organization is a boon for Clinton, who after clinching the Democratic nomination for president will face Republican presumptive nominee Donald Trump in November.

According to the AFL-CIO, the endorsement means the organization will "put in motion its ground campaign to elect Hillary Clinton and union endorsed candidates across the country."

"We will run a sophisticated, targeted ground campaign," Trumka said. "And with the dire consequences Donald Trump poses for America's working families, it has to be."

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