WASHINGTON - As John Kerry clasped hands triumphantly yesterday with John Sweeney, the chieftain of big labor, he clinched his standing with a group whose powers to turn out voters have helped countless Democrats win elections.
But the alliance between Kerry and the labor unions is more complicated than rousing chants and colorful placards might suggest. A weakened labor movement - its political clout diminished after three years of legislative and electoral defeats - must prove that it can, once again, help deliver a victory on Election Day.
And Kerry, a Democrat who has clashed with unions on trade and other issues in his two decades in Congress, is under intense pressure to prove himself worthy of labor's support.
"It is so important that we come together now to put a friend of working families in the White House," Sweeney told union members outside the AFL-CIO as he announced that its 64 unions - representing 13 million workers - had voted unanimously to endorse the Massachusetts senator.
Still, in Kerry, labor is settling for a candidate who has not been a particularly strong ally in the past and in whom, some strategists say privately, their trust is far from ironclad.
"I will fight for the working men and women who define the soul of America," Kerry declared yesterday before the cheering crowd. He pledged that, as president, he would insist that trade agreements require other nations to enforce labor and environmental protections.
But Kerry voted for the 1993 North American Free Trade Agreement (NAFTA), which unions blame for shipping hundreds of thousands of jobs out of the United States. He has backed trade deals that let foreign countries ignore job and environmental rules required in the United States - something that unions say puts American jobs at risk. And he supported "fast track," a measure opposed by labor that empowered the president to expedite congressional approval of trade pacts.
The unions are taking a leap of faith that Kerry's positions on NAFTA and other issues will "evolve" in their favor. They are also forsaking Sen. John Edwards, whose central message about protecting working families hews more closely to the unions' agenda.
The Kerry campaign says it's confident that big labor's endorsement will yield dividends as their candidate battles President Bush in coming months.
"These are our foot soldiers," said Stephanie Cutter, Kerry's spokeswoman. "They will be working very hard to turn out the vote for us."
The AFL-CIO started earlier than ever this election cycle building a mobilization program designed to educate union members on workers' issues - targeting undecided voters for the first time - and turn them out to elect a Democrat.
But it could be an uphill battle for a movement that has been in decline for two decades. Labor unions represent just 13 percent of American workers, down from one-fifth in 1983. Labor leaders are still licking their wounds after their defeats last month in Iowa, where their two favored candidates - Rep. Richard A. Gephardt and former Vermont Gov. Howard Dean - suffered crushing losses in the Democratic caucuses.
Still, labor operatives say union members are energized by their opposition to Bush.
"Our membership is very motivated to show up in the general election - probably more so than it ever has been," said Chuck Rocha, the national political director of the United Steelworkers of America.
The unions remain a political force, especially in Ohio, Pennsylvania, Michigan and Illinois, where manufacturing job losses have hit hard. Still, if the unions are to turn out voters for Kerry on Election Day, leaders say, workers must see signs of a more sympathetic trade stance.
Kerry has begun to alter his rhetoric, saying this week that he would "fix" NAFTA and other trade pacts if he won the White House, and promising to write labor and environmental rules into trade deals. But his past votes could be a major obstacle.
Kerry "well understands that when we go to talk to our members about where he stands on these issues, we have to have something positive to talk about," said Donald Kaniewski, legislative and political director of the Alliance for Economic Justice, a coalition of 19 industrial and manufacturing unions that has endorsed Kerry. "He knows that to adequately address the concerns that he himself has expressed, he may need to move somewhat."
Kerry has "got to be much tougher on [trade] and much more sensitive ... to workers in this country," says former Rep. David E. Bonior of Michigan, a professor of labor studies at Wayne State University and an Edwards backer. "If he isn't, then I think he's going to have problems with the labor base in terms of enthusiasm."
Some labor leaders say it remains to be seen how hard union members will work for Kerry. "The level of enthusiasm you'll see in the general election will depend on how things play out in the primaries and the debates," said Gerald W. McEntee, the president of the American Federation of State, County and Municipal Employees.
But others say they will have little problem convincing rank-and-file workers that Kerry will be better for them than Bush.
"We are very confident that when we reach out to union households about the issues, and compare where the Bush administration is and where the Kerry administration will be, and where the Kerry record has been, they will vote for their own self-interest and support him," said Karen Ackerman, the AFL-CIO's political director.
Kerry also faces pressure from pro-trade centrist Democrats, who warn that tacking too far toward the unions' stance could dampen enthusiasm among more moderate and swing voters.
"Most of the Democrats have been moved toward a position that's closer to labor's on trade in this primary season, and they need to be careful not to embrace an approach that will make it impossible to expand trade and open foreign markets," said Will Marshall, the president of the Progressive Policy Institute, the council's think tank, and an adviser to Kerry.