The 1.6-million-member Service Employees International Union was set to announce it was backing Dean on Thursday afternoon. But at the last minute, the union said it would hold off on an annoucement until next week, at the request of Gerald McEntee, president of the American Federation of State, County and Municipal Employees.
"We have reached a decision and we are hopeful that there are other unions who share our members excitement for Dr. Dean's candidacy," SEIU President Andy Stern said.
Stern said the union's endorsement would be announced Wednesday.
Dean was the only candidate to meet Thursday with members of the SEIU board, and he appeared at a union news conference wearing an SEIU jacket with the words, "Dr. Dean."
It has been a great process and a great pleasure," Dean said, adding that "on Wednesday we're going to have a lot more to say."
Top SEIU officials told at least three Democratic campaigns Wednesday night that Dean was getting the union's endorsement.
SEIU spokeswoman Sara Howard said Dean was the only candidate being considered, but the board could decide not to endorse anyone.
"Local leaders who comprise SEIU's executive board will come together to decide whether the union should endorse," she said. "Until they vote on that question, any speculation as to the result of that vote is just that — speculation."
But other officials said it was a done deal for Dean, the former Vermont governor and Democratic front-runner.
In an appearance on CBS News' "The Early Show," Dean said, "It's going to help our campaign and the Democrats enormously if we could get that endorsement because it does mean we have a great chance to take back the White House."
The endorsement is a blow to Dick Gephardt, who has staked his second try for the White House on the support of organized labor. In his 27 years in the House, the Missouri congressman has carried labor's banner on trade legislation and other issues. But for SEIU and other large service unions, defeating President Bush in next year's election trumps loyalty.
Backing from SEIU, the largest union under the umbrella of the AFL-CIO, provides Dean with thousands of crucial ground troops in early primary states and helps him diversify his campaign. The union represents janitors, health care workers and other service employees, many of whom are minorities and women.
SEIU's endorsement also could shake loose support from other unions — possibly even from its rival, AFSCME, which has remained neutral so far.
Dean is a major contender for AFSCME's endorsement. John Kerry and Wesley Clark also are being considered.
AFSCME, with 1.5 million members, previously had targeted early December for an endorsement but moved up the timetable when the SEIU decided to act this month.
AFSCME's endorsement is considered the holy grail for Democrats because the union spends more money on elections than any other. Its president, Gerald McEntee, was key to Bill Clinton's 1992 campaign success by providing crucial, early support when other unions were backing Sen. Tom Harkin of Iowa.
SEIU and AFSCME initially overlooked Dean as a marginal, quirky candidate from a small state. But that changed as he surged in fund raising and state polls in key states such as New Hampshire and Iowa and began attracting large, boisterous crowds.
SEIU has mapped an aggressive, intensive voter mobilization effort for 2004 that includes making 7 million phone calls, distributing 6 million fliers, visiting 10 million homes and running six mobile action centers in converted tractor-trailers.
Union officials also plan for 500,000 members to donate to the effort, totaling $20 million.
SEIU is the largest union in the early primary state of New Hampshire, with 7,500 members. It also has a large presence in other early primary states, including Michigan, with 45,000; Wisconsin with 10,000; and Washington, with 50,000.
In delegate-rich states such as California and New York, SEIU has 530,000 and 350,000 members, respectively.