Former Gov. John Baldacci on Wednesday became the third prominent Democrat to bow out of the high-profile race for a U.S. Senate seat his party was given a shot at winning when Republican Olympia Snowe decided to retire.

Baldacci joined Democratic Reps. Chellie Pingree and Mike Michaud in forgoing a race that became more complicated with the entry of independent former Gov. Angus King, widely recognized as the front-runner in a three-way contest.

Baldacci said he didn't want to relocate his family because his wife has a job in Bangor and his son is a University of Maine student. He also didn't like the idea of traveling back and forth between Washington and Maine as he did during eight years in the U.S. House.

"That's really what it came down to. You can take the boy out of Maine, but you can't take Maine out of the boy," the Bangor native told The Associated Press.

Potential candidates were forced to make quick decisions after Snowe's announcement two weeks ago that she wouldn't seek a fourth term because of partisanship and polarization in the Senate. She was expected to win easily.

Thursday is the deadline for candidates to submit the 2,000 signatures necessary to get on the June primary ballot.

Within 24 hours of Snowe's announcement, Pingree announced she was collecting signatures. But Michaud surprised observers by quickly announcing he'd defend his House seat instead of running for Senate. Pingree followed suit a day after King, a former Democrat, announced he would run.

King's entry caused Democrats to think twice in a state where there are more unenrolled voters than in either of the major parties.

Without better-known candidates, Democrats are hurting their prospects for the seat they initially thought they had a good chance to win, said Ethan Strimling, a political analyst and Democratic activist in Portland.

If donors pull back, Democrats run the risk of finishing third as they did in 2010 when tea party-backed Republican Paul LePage was elected governor, followed by independent Eliot Cutler and Democrat Libby Mitchell.

"Democrats are putting themselves in a very precarious position," he said.

The scenario of a three-way Senate race strikes fear into some Democrats for another reason _ they believe King and Democrats could split the vote in a way that gives an advantage to Republicans, who are seeking to regain control of the Senate.

Four Democrats previously announced they were running for the seat. One of them, former Secretary of State Matthew Dunlap, submitted his petitions Wednesday. Among Republicans, at least five candidates had declared interest.

Baldacci, who was governor from 2003 to 2011 after leaving Congress, said he's frustrated by congressional inaction on issues like energy independence, health care and the economy, and he wants to remain involved in attempting to make changes.

"We're going to work to improve the economy and the environment and the future for our children, and we're going to be able to make changes. We're just going to be doing it from Maine," the 57-year-old said.

For the past year, Baldacci has served as director of the Department of Defense's Military Health Care Reform Initiative. When the Pentagon posting comes to an end March 23, he'll return to Holden, Maine, and will remain engaged in public service, he said.

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Associated Press writer Glenn Adams in Augusta contributed to this report.

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