WASHINGTON (Reuters) - One of the biggest U.S. trade unions made an unusual dual presidential endorsement of Democrat Hillary Clinton and Republican Mike Huckabee on Thursday, while Democrat John Edwards won the 2008 backing of the carpenters' union.
For Edwards, a former North Carolina senator and 2004 vice presidential nominee, the support of the 520,000-member United Brotherhood of Carpenters and Joiners was a breakthrough after months of careful courting of organized labor.
"Our endorsement is based on the senator's outspoken support for all of organized labor and his focus on America's working families," Carpenters President Douglas McCarron said in a statement.
The International Association of Machinists and Aerospace Workers, which has about 720,000 active and retired members, backed a candidate from each party for the first time after a recent survey found about one-third of union members voted Republican and two-thirds Democratic.
"The dual endorsement is intended to involve all IAM members in the upcoming election," said IAM International President Tom Buffenbarger.
The machinists' endorsement was made at the union's national conference in Orlando, Florida. Huckabee, the former governor of Arkansas, was the only Republican to address the labor group.
Huckabee has lagged behind the top Republican 2008 contenders in national polls and fund raising but received a boost earlier this month with a surprise second-place finish in the Iowa straw poll.
"Mike Huckabee was the only Republican candidate with the guts to meet with our members and the only one willing to figure out where and how we might work together," Buffenbarger said in a statement.
The union endorsement was the second of the week for Clinton, a New York senator who leads the Democratic field in national polls 14 months ahead of the November 2008 election. She won the backing of the smaller United Transportation Union on Tuesday.
"Hillary Clinton earned the IAM's endorsement by focusing on jobs, health care, education and trade -- the bread and butter issues of the American middle class," Buffenbarger said.
The carpenters and machinists' unions were the third and fourth unions to make endorsements in the 2008 race this week. Several more unions are expected to back contenders in the next few weeks after the national AFL-CIO freed its 55 member labor unions to make their own choices earlier this month.
Democratic Sen. Chris Dodd of Connecticut won the endorsement of the International Association of Fire Fighters on Wednesday.
The endorsements offer financial and grass roots muscle for presidential candidates, and Edwards in particular has focused on building support among union members, a core Democratic constituency.
The carpenters' union had been courted by President George W. Bush since the 2000 election and did not make an endorsement in 2004.