HARTFORD, Conn. — Sen. Joe Lieberman, who angered Democratic voters with his staunch support of the war in Iraq, on Tuesday narrowly lost his party's nomination to Ned Lamont, an antiwar candidate who was unknown seven months ago.
Lieberman is only the fourth incumbent senator to lose his party's nomination since 1980. He promised to run for a fourth term as an independent candidate. Looking out at his supporters Tuesday night, he beamed and raised a fist defiantly in the air.
"The old politics of polarization won today," he said. "For the sake of our state, our country and my party, I cannot and will not let that result stand."
The race, initially predicted as a blowout victory for Lieberman, became a lesson in how the war in Iraq has reshaped partisan politics. In Lamont's headquarters, a jubilant crowd celebrated an upset win that, last year, would not have seemed possible.
Lamont thanked Lieberman for "the grace and dignity with which he has served our state for many years," and vowed to act as an agent for change.
"Some call Connecticut 'the land of steady habits.' Connecticut voters do not call for change lightly, but today we called for change decisively," he said. "No more 'stay the course.' Stay the course is not a winning strategy in Iraq, and it is not a winning strategy in America."
Lamont, a wealthy cable executive, led Lieberman by less than four percentage points, with 51.8% of the vote to Lieberman's 48.2% with 99% of precincts reporting. Several of his supporters -- among them Rep. Maxine Waters (D-Los Angeles) -- said they hoped Lamont's win would prove to be a transforming moment for the Democratic Party.
"I believe this is the most significant election of all the Democrats that are running," Waters said. Many elected officials, she said, "could not bring themselves to stand up against this war because they thought they didn't have public support. Ned Lamont's courage will give courage to a lot of people."
As the race drew national attention this summer, nearly 30,000 new voters either registered as Democrats or switched their registration for the chance to vote in the primary. Turnout was close to 40%, which is 15 percentage points higher than the previous recorded turnout for a Connecticut primary.
An independent Lieberman campaign will force an awkward choice for state Democratic leaders: fully shift their support to the novice politician who has the party's backing, or stick with Lieberman. They must make that decision before 11 a.m. today, when Democrats will gather for a public "unity meeting," said Steven Donen, a consultant and Lieberman supporter.
"Do they appear with [Lamont] jointly? Do they raise money for him?" Donen asked. "Don't you support your friends through thick and thin, no matter what?"
Leslie O'Brien, a past executive director of the state Democratic Party, said there was no question that Democrats would embrace Lamont; the question is "how warmly." George Jepsen, a former chair of the state party who worked with Lamont's campaign, said he expected the shift to go smoothly.
"I've had people who have come up to me and said, 'George, I'll write him a check on Aug. 9,' " he said.
A year ago, Lieberman was considered so popular and well-financed that no established Democrat could be induced to run against him. Lamont officially declared his candidacy in March, five months before the primary. In January, when he began campaigning against Lieberman, his statewide name recognition was 4%, campaign manager Tom Swan said.
Lamont, 52, poured $2.5 million of his own money into launching the campaign and paid dozens of visits to small-town Democrats whose frustration with Lieberman was building. The challenger's vigorous, plain-spoken broadsides against the war attracted the attention of progressive activists and bloggers.
From the beginning, most prospective Lamont voters said they were supporting him out of dislike for Lieberman. In a Quinnipiac University poll released Monday, 54% of Lamont voters said that was the main reason they support him.
"Not to say anything bad about the Lamont campaign," said Kenneth Dautrich, a public policy professor at the University of Connecticut, "but this has always been about Lieberman."
Lieberman became a Democratic star in the '90s, a time when the party worried about losing touch with an increasingly conservative electorate.
The son of a liquor store owner in Stamford, Conn., Lieberman began running for office as a high school student and never stopped. At Yale University, he wrote an admiring senior thesis on John M. Bailey, Connecticut's cigar-chewing political boss whose motto was "You gotta do what you gotta do."