The presidential campaign for New York Sen. Hillary Rodham Clinton has announced the endorsement of the American Federation of State, County and Municipal Employees, the nation’s largest public sector union.

In total, AFSCME represents more than 1.4 million workers. The union has said it has plans to activate a 40,000-member voluntary force and launch a get-out-the-vote effort in Iowa, where it represents 30,000 workers.

The union raised eyebrows early in 2004 when it withdrew its endorsement from former Vermont Gov. Howard Dean. The group, along with the Service Employees International Union, had endorsed Dean in November 2003 when he was the frontrunner for the Democratic presidential nomination in terms of both national polls and fund raising. The endorsement was withdrawn when Dean failed to produce results in early states including Iowa and New Hampshire.

“Clinton has the leadership, ideas and strength to lead America in a new direction and her commitment to working families is unparalleled,” said Danny Homan, AFSCME Iowa Council 61 president. “We face serious challenges at home and abroad, and she is the best candidate to restore middle class economic progress, support our soldiers and veterans, and improve the quality of life for all Americans.