One of the country's largest unions announced Monday that it was withdrawing its support for Democrat Howard Dean (search), a blow to the one-time front-runner's staggering presidential campaign.

Making public the bad news it delivered to the candidate in a face-to-face meeting two days ago, the American Federation of State, County and Municipal Employees (search) said it "has ended its activities on behalf of the Dean campaign and is shifting its resources to the general election."

The 1.5 million-member union brought heft to Dean's campaign last fall with its endorsement, but the decision to pull the plug on the former Vermont governor indicates just how far the campaign has fallen.

"We agree that the most important priority for America's working families is to defeat George W. Bush," AFSCME President Gerald McEntee said in a statement. "We will continue to work together to unify the Democratic Party to do just that."

Union officials would not rule out an endorsement of front-runner John Kerry. Campaign strategists say McEntee probably will want to join the flood of union endorsements headed Kerry's way, especially because he considered the Massachusetts senator before backing Dean.

A coalition of unions that supported Dick Gephardt, called the Alliance for Economic Justice, will announce its endorsement of Kerry early next week. The alliance includes the Teamsters and other blue-collar unions.

McEntee told Dean of the decision to withdraw at a Saturday meeting in Burlington, Vt. For now, Dean still holds onto his two other union endorsements: the Service Employees International Union (search), the largest in the AFL-CIO, and the International Union of Painters and Allied Trades.

Dean, who had said he must win Wisconsin on Feb. 17 to remain in the race, said Tuesday he intends to continue his campaign regardless of the outcome next week.

But AFSCME, which spends more on politics than any other union, wanted to immediately stem the bleeding of manpower and campaign coffers to a losing campaign.

McEntee is a major player in Democratic Party politics, and his early endorsement of Bill Clinton helped propel the then-Arkansas governor to the presidency. But the union leader is no kingmaker this year. He had flirted with backing Kerry and Wesley Clark at different points last year, before jumping on Dean's bandwagon when the former Vermont governor was leading in polls and fund raising.

Dean's loss of AFSCME denies him valuable organizers, money and political contacts at the worst possible time: He is fighting for his political life after going winless in the primary season to date.

Dean, in the joint statement, said he was committed to staying in the race.

"Since my days as governor of Vermont I have always advocated for the well-being of public service employees who are on the front lines of solving the critical problems facing our nation," he said. "AFSCME and its members are a tireless and effective part of the political process and will continue to play a leading role in this election."