Four years ago, he was the toast of the Jewish world, the favorite son who became a symbol of opportunity for American Jews in the United States.
But when he went out on his own this time around, Sen. Joseph Lieberman (D-Conn.) failed to catch on as a top-tier candidate.
Lieberman formally stepped down Tuesday night, after failing to win any of the nine primaries or caucuses since the presidential season began. He came in second in only one of seven contests Tuesday, in Delaware.
"The judgment of the voters is now clear," he told supporters at his headquarters in Virginia.
It had been clear for a while. Even Lieberman's mother, Marcia, had acknowledged earlier that her son's campaign "didn't catch on."
Now the question will be asked for years to come: What went wrong?
Was his religion a factor -- especially for Jews? Are his politics out of sync with Democratic voters? Was it his style?
There are many explanations for Lieberman's fall.
Some say it was political. Lieberman is a moderate on social, economic and political issues, someone who supported the Iraq war and was campaigning among a Democratic electorate angered by the Bush administration's handling of Iraq and his domestic policies.
In his announcement, Lieberman said he still believed that moderation was the best way to go. "I offered a mainstream voice and I still believe that that is the right choice and the winning choice for our party and our country," he said.
While that positioning might have served him well against Bush in November, it missed the point of Democratic primaries -- playing to the party's base.
Others say his mistakes were strategic, suggesting that Lieberman had a sense of entitlement because of the election controversies of 2000, and therefore did not lay the groundwork for his candidacy the way his opponents did.
Then there is the Jewish question.
While no one expected Lieberman to receive the full support of American Jews, some Lieberman loyalists say they did not anticipate the extent to which his candidacy would be rejected by some in their community.
Rabbi Irving "Yitz" Greenberg, president of the Jewish Life Network Foundation, and his wife Blu, were circulating an op-ed to Jewish newspapers this week, arguing that Jews were acting as anti-Semites would, casting Lieberman aside because of his Jewishness.
"The community blinked," Yitz Greenberg said, suggesting that his policies were "a good fit" for Jews.
A rise of anti-Semitism and anti-Zionist sentiment around the world brought old fears to the surface for many Jews, he argued, and Jews looked for a safer choice for president.
"The community made a huge mistake," he said. "A victory for a Jew in America would have been a tremendous refutation of anti-Semitism."
Some Jewish donors said they would have given to Lieberman, based on his political stances, but did not want to support a Jew at this time.
It was easier to support Lieberman as a vice presidential nominee, some Jews say, because he was blazing the trail without being the center of attention.
But as his own candidate -- and at a time with increased tension in the Middle East and an uptick in international anti-Semitism -- hesitancy grew.
Marvin Lender, a member of Lieberman's campaign board who raised funds for him in the Jewish community, suggested that Lieberman aides had anticipated raising more money from the Jewish community.
He blames the fear as one element, but says the Jewish community's political sophistication also hurt Lieberman's chances.
"Many leaders of the Jewish community, the politically invested people, had already made commitments," he said.
Indeed, many seasoned political donors in the Jewish community had ties to other candidates -- such as Sen. John Kerry (D-Mass.) or Rep. Richard Gephardt (D-Mo.), or several of the candidates at once.
It was much easier to support Lieberman in 2000, when he was not running against other Democrats.
No one suggests that the mixed reaction Lieberman received from Jews is the whole story of his candidacy's demise. Many say the candidate did not work hard enough to build off of the name recognition and exposure he received as Gore's running mate in 2000, reaching out to party contributors in key primary states.
"Unfortunately, he spent two years not doing anything, resting on that flash reputation," said Steve Rabinowitz, a Democratic media strategist. "He didn't develop it, he didn't go out and meet big givers and local leaders and mayors."
Some say Lieberman had a sense of entitlement, assuming that Democratic anger over the Florida recount, the Supreme Court decision signaling the defeat of the Democrats that year, and the fact that Gore and Lieberman won the popular vote, would be enough to bring voters to his side.
His campaign appearances often reflected on his 2000 experiences.
"What a shame 2000 was," Lieberman told a retirement community in Boca Raton, Fla. in October. "We had the votes, but not the five votes on the Supreme Court."
When Lieberman campaigned last year, voters remembered the war in Iraq, which Lieberman supported, and the Sept. 11, 2001 terrorist attacks a lot more clearly than they did the 2000 election scandals.
He suggested Tuesday night that he would continue to channel the anger left over from 2000 -- but now, in service of whomever wins the nomination, pledging to "deny George Bush a second term."
Others say that he was handicapped by his choice to wait to launch his campaign this year until Gore decided not to enter the race. However, Gen. Wesley Clark entered the race late, but has fared better than Lieberman.
Lieberman did not stress his electability enough on the trail, analysts suggested.
"Voters wanted somebody who could really stick it to Bush and is confrontational and aggressive," said Steve Rothenberg, an independant political analyst.
That wasn't Lieberman.
"He's like your favorite uncle, but he doesn't portray that kind of dynamism," Rothenberg said. "He doesn't cut a big political profile."
He was true to form Tuesday, starting his drop-out speech by congratulating rivals Sen. John Kerry (D-Mass.) and Sen. John Edwards (D-N.C.) for their wins, and praising all the others for fights well fought.
Jewish political leaders say that despite his poor showing, Lieberman's candidacy was historic.
Only two other Jews have tried to seek the presidency -- Sen. Arlen Specter (R-Pa.) in 1996 and the late Pennsylvania Gov. Milton Shapp in 1976 -- but neither got as far as Lieberman.
"He has carried himself as a national candidate and handled masterfully the few times people brought up his religion," said Ira Forman, executive director of the National Jewish Democratic Council.
"In doing that, even that small gesture, he has blazed a path for future candidates who might one day be president of the United States."
Lieberman never shied away from his faith, citing it as an inspiration Tuesday night. He ended his concession speech by paraphrasing traditional morning prayers, saying he would continue "to serve the Lord during the day with as much gladness and as much purpose as I can."
Lieberman supporters, frustrated by how their candidate did in the Jewish community, suggest more dialogue is needed to convince Jews that having a member of the tribe in the White House is not a bad thing.
"We have to square our shoulders and look at these issues directly and talk more about it," said Blu Greenberg, founding president of the Jewish Orthodox Feminist Alliance.
"We have to examine how comfortable we are with our standing as citizens of the United States and as citizens of the world."