"We don't have the luxury of fighting among ourselves," Gore said in a two-state endorsement tour designed to answer critics of Dean's foreign policies and those who doubt his ability to defeat President Bush.
Gore said Dean "really is the only candidate who has been able to inspire at the grass-roots level all over the country." He said the former Vermont governor also was the only Democratic candidate who made the correct judgment about the Iraq war.
"I realized it's only one of the issues, but my friends, this nation has never in our two centuries and more made a worse foreign policy mistake," Gore told the Iowa crowd.
Their hands joined and raised above their heads, Gore and Dean began their political marriage of convenience in New York's Harlem community - homage to the candidate's bid to draw minority voters to his campaign. At Gore's behest, they flew together to Iowa, site of the Jan. 19 kickoff caucuses won by the former vice president three years ago. BEGIN POSITION 3 END POSITION 3
Dean is locked in a tight race with Rep. Dick Gephardt of Missouri in the state.
Addressing the fear of some Democrats that Dean's blunt-speaking ways will cause political trouble for the ticket, Gore told the Iowa crowd, "I think people realize that he sometimes speaks off the cuff, but they realize also that this is a result of him speaking from the heart. And he doesn't hold back.
Dean said it was an honor and a privilege to receive Gore's endorsement and advice, but he said only voters will determine whether it means anything.
"It doesn't solidify anything," he said of the nod, adding that it's unclear what Gore's role will be in campaigning for Dean.
Gore's political impact was immediately evident at the New York event when Roy Neel, a longtime operative, pledged to join Dean's campaign, bringing his network of Gore supporters with him.
While praising the party's other presidential candidates, Gore said Democrats should unite behind Dean or at least stop attacking him.
"We don't have the luxury of fighting among ourselves to the point where we seriously damage our ability to win on behalf of the American people," Gore said just hours before the candidates debated in New Hampshire.
Gore won the popular vote by half-a-million votes in 2000 but conceded to Republican George W. Bush after a tumultuous 36-day recount in Florida and a 5-4 Supreme Court vote against him. The election still rankles Democratic activists, many of whom are still loyal to Gore.
The approval of Bill Clinton's No. 2 bolsters Dean's case that he can carry the party's mantle in November and represents more than an Internet-driven outsider relying on the support of largely white, upscale voters.
Dean hopes the coveted endorsement also eases concerns among party leaders about his lack of foreign policy experience, testy temperament, policy flip-flops, campaign miscues and edgy anti-war, anti-establishment message.
"What this says is that all these Washington insiders who have been gnashing their teeth, wringing their hands and clinging to their cocktail cups can relax now. Dean's been knighted by the ultimate insider," said Democratic consultant Dean Strother of Washington. "It's game, set and match. It's over."
Other Democrats offered more cautious appraisals, but the overwhelming consensus was that Dean's coup makes him the overwhelming favorite to claim the nomination. Even advisers to Dean's rivals conceded they were stunned and disheartened by the news.
"I was caught completely off-guard," Sen. Joe Lieberman, Gore's running mate in 2000 and a hopeful for the nomination, said Tuesday on NBC's "Today" show. An official close to Gore, speaking on condition of anonymity, said the former vice president tried repeatedly Monday to contact Lieberman but did not hear back.
Asked on "Today" whether he felt betrayed by the former vice president, Lieberman said, "I'm not going to talk about Al Gore's sense of loyalty this morning."
Lieberman complained that Gore and Dean differed on many issues, though Lieberman himself parted with Gore on several matters in 2000.
Jenny Backus, a Democratic strategist from Washington, said Gore will help Dean gain access to "some key constituencies, African-Americans and women and organized labor, and in Iowa."
But while Dean leads in polls in New Hampshire and Iowa, the race has not taken shape beyond the initial voting states and Gore's endorsement will not erase every doubt about the former Vermont governor. Analysts noted that Gore's uneven performance in 2000 alienated many party leaders, thus his endorsement has limited appeal, and they predicted an anti-Dean movement will eventually form behind one of his eight rivals.
Some rank-and-file Democrats were stung by Gore's decision.
"It isn't fair that he turned his back on Lieberman," said Mohammed Islam, a New York taxi driver and longtime Democratic voter. "If he was good enough for him in 2000, why not now?"
In an unusual response, Democratic candidate Wesley Clark issued a statement touting the number of former Gore staffers working on his campaign.
The White House had little reaction to Gore's endorsement, which spokesman Scott McClellan called "all part of the Democratic primary." However, McClellan rejected Gore's charge that invading Iraq had been a "catastrophic mistake" by Bush.
"The president has worked to make the world a safer and better place, and America more secure for future generations," McClellan said.