Union President James P. Hoffa (search) delivered the news of the coveted, yet anticipated, labor prize to Gephardt after the morning vote of 22 vice presidents by conference phone call, union officials said, speaking on the condition of anonymity.
Teamsters spokesman Bret Caldwell confirmed that an endorsement decision was reached but refused to identify the candidate. A formal announcement will be made in Detroit on Aug. 9, he said.
Events also are scheduled for Des Moines, Iowa, and Manchester, N.H., -- early election states -- with Hoffa and Gephardt, The Associated Press has learned.
Unions have agreed to hold their endorsements until after next week's AFL-CIO (search)meeting in Chicago.
A labor trophy from the nation's most recognizable union, the most high profile to date, will give Gephardt's struggling presidential bid a substantial boost.
"There are unions and there are unions with capital letters," said Larry Sabato, director of the Center for Politics (search) at the University of Virginia. The Teamsters union "is a capital letter union. They back their designated candidates with lots of money and volunteers."
It couldn't come at a better time for the former House minority leader from Missouri who has been plagued by concerns about his ability to excite Democratic voters -- a factor highlighted in his recent poor showing in the money race.
The Teamsters' endorsement is a slap at the Bush White House, which has tried to chip away at organized labor's solid support for the Democratic Party. Hoffa even secured a special seat at Bush's first State of the Union speech.
The Teamsters were Bush's obvious target, with the union's past endorsements of his father and Republican presidents Reagan and Nixon.
For Gephardt, who has staked his presidential hopes on the support of organized labor, the endorsement was widely expected -- but just not so early.
Teamsters officials haven't been shy about their affection for Gephardt, whose father, a milk truck driver, was a member -- a point the candidate constantly highlights.
"He's certainly the best candidate for working families and has stood strong with the Teamsters throughout his entire career," Caldwell said.
Despite the Teamsters approval, Gephardt's support among other Democrats has remained tepid. He lagged well behind serious contenders in second-quarter fund raising, collecting just $3.87 million for fifth place.
Another problem for Gephardt is that he has been down this road before.
In the 1988 presidential race, he drew early attention with his focus on trade and the poor economy, winning Iowa and finishing second in New Hampshire. But then he ran out of money and fizzled.
"Gephardt needs all the help he can get," Sabato said. "He's still fighting the image of being yesterday's man."
Backing from the Teamsters, which claim 1.4 million members, will give Gephardt a bounce heading into Chicago next week for an AFL-CIO-sponsored presidential forum.
Union leaders there also will assess whether Gephardt has enough support among other unions to secure a labor-wide endorsement. He is the only candidate who stands the chance.
Word of the Teamsters' endorsement plans came after Gephardt had spoken with reporters Thursday about new endorsements from two small maritime unions.
"What unions give you is both resources and people -- ground troops" to help the campaign organize in states, he said.
The Teamsters have 3,500 members in New Hampshire and 10,000 in Iowa.
His longtime allegiance and his unwavering opposition in congressional battles over free-trade agreements that decimated many unions, including the Teamsters, helped him secure the endorsement, Teamsters officials said.