The former House minority leader came here hoping to build on the labor support he already has garnered in his race against nine other Democrats.
But on Wednesday, a day after labor leaders and hundreds of rank-and-file heard appeals from Gephardt and his competitors, the governing executive council decided that no endorsement would come at this meeting.
Gephardt had hoped to get the union label as labor's favorite in the Democratic delegate-selection contests. But the AFL-CIO has done that only twice before -- giving the prize to Walter Mondale and Al Gore.
The federation's executive council, which met here this week, does not itself have authority to endorse candidates. But it could have voted to recommend its favorite to the larger AFL-CIO general board, on which union presidents from all 65 affiliates sit.
The executive council did vote Wednesday to give President John Sweeney (search) authority to call an endorsement meeting by the general board on Oct. 15.
Labor leaders have acknowledged that Gephardt is the only Democrat who could reach the lofty threshold of an endorsement by at least two-thirds of the affiliates representing the federation's more than 13 million rank-and-file members.
But no endorsement recommendation came out of this week's meeting here, and that was sure to hearten Gephardt's rivals.
"We're going to come back in October and do it," said Teamsters (search) President James P. Hoffa, whose union will officially endorse Gephardt on Saturday. "He's going to be a very hot item when he starts hitting the trail," Hoffa said of Gephardt.
Gephardt has staked his presidential aspirations on support from organized labor. His challenge is to convince skeptical leaders of the large service and public sector unions that he is a viable candidate.
One of those unions is the Service Employees International Union (search), the federation's largest with 1.6 million members.
"There's only one issue here: Dick Gephardt," said President Andrew Stern. "Dick Gephardt has the greatest and most passionate labor support of any candidate. The question is how broad is that support."
So far, it's 11 unions with more than 3 million members.
The nine contenders played to labor leaders in the AFL-CIO's presidential forum Tuesday night, offering ambitious plans for health care coverage and restrictions on trade agreements, and criticizing the Bush administration for plans to change overtime pay regulations.
Gephardt, whose introduction garnered the loudest applause Tuesday, reminded the forum's 2,000 union member audience that he has been a longtime labor ally.
"I've simply tried to represent people like my parents, the people that make this country great, like you," he said, saying his father drove a milk truck and was a Teamster, and his mother was a secretary.
But other candidates want to deny Gephardt the AFL-CIO endorsement, and they used the forum to show that they too were friends of labor.
"My father worked in a mill all his life. I was the first person in my family to go to college," said North Carolina Sen. John Edwards. "And when I was young I myself worked in the mill with my father."
Massachusetts Sen. John Kerry (search) had a tough night with a hoarse voice. He has generated a lot of interest from SEIU and another large, powerful union, the American Federation of State, County and Municipal Employees, and is the Democrat with the best chance of denying Gephardt the AFL-CIO prize.
Kerry told the union officials and other Democrats why he thinks he has the best chance to beat Bush.
"I cannot wait to stand up and remind him that having a skilled Navy pilot land you on an aircraft carrier in a borrowed suit does not make up for losing 3 million jobs," said Kerry, a decorated Vietnam War veteran.
Connecticut Sen. Joe Lieberman continued his pitch to moderate Democrats, taking some unpopular stands with the liberal, union audience. He was booed at one point for saying he would support a pilot vouchers program to send poor children to private schools.
"I'm going to speak the truth. I'm going to say what I think is best for America regardless," he countered.
Ohio Rep. Dennis Kucinich hammered all the candidates, citing their mixed records on issues such as free trade and Social Security.
Al Sharpton arrived late and joined his eight rivals on stage with the forum already under way. "I had a nonunion cab driver," he quipped.