DES MOINES (AP) – Democrat Tom Vilsack, the former Iowa governor who built a centrist image, abandoned his bid for the presidency on Friday after struggling against better-known, better-financed rivals.

“It is money and only money that is the reason we are leaving today,” Vilsack told reporters at a news conference, later adding, “We have a debt we’re going to have to work our way through.”

Vilsack, 56, left office in January and traveled to early voting states, but he attracted neither the attention nor the campaign cash of his top-tier rivals – Sen. Hillary Rodham Clinton, Sen. Barack Obama and John Edwards. He even faced obstacles in his home state.

In the most recent financial documents, Vilsack reported raising more than $1.1 million in the last seven weeks of 2006 but only had around $396,000 in the bank. Some campaign finance experts contend candidates will need $20 million by June 2007 to remain viable.

“I came up against something for the first time in my life that hard work and effort couldn’t overcome,” he said, his wife, Christie, and two grown sons at his side. “I just couldn’t work any harder, couldn’t give it enough.”

Vilsack’s withdrawal still leaves a crowded field of eight Democrats. He will remain an important figure in the presidential race as former rivals undoubtedly will seek his endorsement and help to win Iowa.

Vilsack, who likely will be considered as a vice presidential nominee, repeatedly declined to endorse another candidate at his news conference.

Other campaigns immediately began to seek out Vilsack’s well-respected staff, hoping to pick up talented political operatives with experience in the first nominating state, and his political backers.

Gary Hirshberg, CEO and founder of Stonyfield Farm yogurt, was one of Vilsack’s earliest and most prominent New Hampshire supporters. He said two minutes after Vilsack’s announcement, Obama called seeking his support. Hirshberg told Obama he wasn’t ready to commit to another candidate yet.

“Although we’re absolutely undecided, I was very impressed,” Hirshberg said. “Though we can wring our hands now about the role of money in these campaigns, it’s still really vindicating to me to see, particularly here in New Hampshire, that grass-roots, house-to-house, person-to-person politics is still the order of the day. I think Senator Obama just proved that.”

Vilsack was the first Democrat to formally enter the 2008 race when he announced his candidacy in November. His February departure underscores the warp speed of the 2008 race. In previous presidential cycles, candidates didn’t announce until the fall, just a few months before the first caucuses and primaries, not more than a year before.

Trying to counter perceptions that as one of the least known of the prospective candidates he was too much of an underdog to succeed, Vilsack said in a campaign video: “I’ve never started a race that I’ve been expected to win, and I’ve never lost.”

But the struggle for money proved too difficult, leaving a debt that Hirshberg described in the “hundreds of thousands.”

“I told Tom last night that a number of us intend to get to Des Moines after the dust settles and help retire that debt, to do something, even if we have to sell yogurt in the street,” Hirshberg said.

As governor of Iowa, Vilsack had carved out a reputation as a centrist balancing his state’s budget and refusing to raise taxes, while emphasizing increased spending on such priorities as education, health care and higher wages. Until recently he chaired the Democratic Leadership Council, the party’s signature centrist group.

Vilsack initially made the focus of his long-shot campaign a plan to end U.S dependence on foreign oil by promoting alternative energy sources.

“Energy security will revitalize rural America, re-establish our moral leadership on global warming and climate security, and eliminate our addiction to foreign oil,” Vilsack, a prominent proponent of ethanol, biodiesel and wind power, said at the time.

More recently, Vilsack has been among the more aggressive Democratic candidates in his call to bring U.S. troops home from Iraq, calling for Congress to cut off funding.

Beyond his record as governor, Vilsack tried to sell himself as a candidate with a compelling personal story, which he hoped would spark national interest in his candidacy. He was left as an infant at a Catholic orphanage in Pittsburgh and adopted by what he has described as a “troubled but loving family.”

His parents were well-to-do and sent him to a private preparatory school, but his mother was an alcoholic who beat him and his father suffered trying financial reversals.

Vilsack managed to transcend his difficult childhood to build a successful career in law and politics, serving as a mayor, state senator and two terms as Iowa governor.

In a sign that Vilsack might abandon the race, he recently accepted a position lecturing at the Drake University Law School in Des Moines and had become a consultant for MidAmerican Energy Co.