CNN  — 

AFSCME, the largest trade union of public employees in the United States, endorsed Hillary Clinton for president Friday, according a release from the group provided to CNN.

The endorsement, a key for Clinton, came after the 35 person member-elected board representing American Federation of State, County and Municipal Employees councils and affiliates from around the country voted to back the former secretary of state.

“The next president will make decisions that could make or break the ability of working people across America to sustain their families. That’s why we spent the last six months engaged in the most member-focused, in-depth, and transparent endorsement process AFSCME has ever undertaken,” said AFSCME President Lee Saunders

Saunders added the group was looking for someone to fix the “out-of-balance economy.”

“Members want a candidate who will make it easier instead of harder to join together in strong unions and stand together for wages and benefits that can sustain our families,” he said. “What we also heard was AFSCME members want the candidate who will be the most effective champion for working families, and who will be able to deliver a victory in this critically important election. AFSCME members believe that candidate is Hillary Clinton.”

The decision came after the union had conversations with all candidates, including Clinton, former Maryland Gov. Martin O’Malley and independent Vermont Sen. Bernie Sanders. All three candidates participated in town hall meetings with the unions in Iowa earlier this year and the union used three member polls to gauge which candidates their members we backing.

Polling, according to Saunders, showed that nearly two thirds of AFSCME members would vote for Clinton in the Democratic primary.

The AFSCME endorsement is big for Clinton, who is coming off arguably the best three weeks of her campaign. With the endorsement, the 1.6 million members of the union will provide help on the ground in key states and will be able to back her campaign financially, too.

The national endorsement does not mean that AFSCME state chapters are compelled to endorse Clinton, but the national endorsement is the only backing that comes with organization and money, according to union spokespeople.

The Sanders campaign brushed off the endorsement.

“Bernie is proud to have the grassroots support of tens of thousands of working families in AFSCME and other unions,” Sanders’ spokesman Michael Briggs said.

Republicans were quick to use the endorsement against Clinton.

“Hillary Clinton is now officially beholden to the big government union bosses who routinely put their special interests ahead of the hard working taxpayers,” RNC Chairman Reince Priebus said in a statement. “With their endorsement, its clear AFSCME is counting on Hillary Clinton to block commonsense efforts to reign in Washington’s runaway wasteful spending that is mortgaging our children’s future.”

The union has long been supportive of the Clintons. AFSCME backed Clinton in 2007 and went early for then-Gov. Bill Clinton in 1992.

The union is a major player in Iowa, too, representing 40,000 public employees.