The Vermont Senate's most outspoken member is calling it quits. 

Sen. Peter Galbraith (D-Windham) announced Monday that he won't seek reelection to the Windham County senate seat he's held for nearly four years. Instead, the Townsend resident and former U.S. ambassador to Croatia said he'll refocus on his career in international diplomacy.

"In recent months, I have become increasingly involved in an informal effort aimed at finding a political solution to Syria’s civil war, working with Syria’s Kurdish and Christian minorities to help them develop strategies to best protect their communities," Galbraith said in a written statement. "Reluctantly, I have concluded I cannot do this and still devote the necessary time to my work in Montpelier."

Galbraith's work with an unnamed British nongovernmental organization brought him to Brussels, Paris and Iraq at least one weekend a month during last winter's legislative session. Though he missed only a few votes in the process, he said, striking a balance between his professional and legislative work had grown difficult.

The son of John Kenneth Galbraith, one of the 20th century's most influential economists, Galbraith spent much of his career in top posts in the U.S. Senate Committee on Foreign Relations, the State Department and the United Nations. But after winning election to the Vermont Senate, Galbraith struggled to cultivate allies and accrue influence in the clubby legislative body. 

Instead, Galbraith earned a reputation for speaking frequently and at great length on the Senate floor and for introducing amendments to most major pieces of legislation. To his colleagues, he was, at times, an irritant, but to the press, he was a source of constant amusement.

"It's a sad day for the Vermont press corps," he joked on Monday.

True to form, Galbraith came out swinging even as he announced his retirement, criticizing what he called "the extraordinary influence of lobbyists and special interests" in the Vermont legislature. Throughout his tenure, he argued for stronger campaign finance laws and a ban on corporate contributions to political candidates.

"In case after case, the broader public interest gets trumped by one or two people with special interests," he said. "The other thing that was frustrating about Vermont was the real lack of accountability."

Specifically, Galbraith blamed the owners of Jay Peak Resort for killing legislation he introduced to limit forest fragmentation, and he blamed "one wealthy person" who he would not name for blocking proposed changes to the estate tax. Galbraith also questioned the legislature's approval of a $4.5 million Vermont Enterprise Incentive Fund — proposed by Gov. Peter Shumlin with IBM's Essex Junction plant in mind — without safeguards to protect taxpayers.

"My colleagues are people of good will. But the fact is, the people who can hire lobbyists are the people who are in the room," Galbraith said, adding that he was "shocked" how frequently lobbyists were allowed to speak in committee as lawmakers debated legislation.

Even before Galbraith announced his retirement, two Democrats — Becca Balint of Brattleboro and Joan Bowman of Putney — had announced plans to run for the two Windham County senate seats currently held by Galbraith and Sen. Jeanette White (D-Windham). On Monday, Grace Cottage Hospital CEO and former Vermont secretary of agriculture Roger Allbee announced that he, too, would run.

"I think the health care issue will be a very, very important thing not only for institutions like Grace Cottage, but for our patients as well, and I want to be a part of that," Allbee said.

Though he worked in former governor Jim Douglas' administration and ran for the House as a Republican in 2004, Allbee said he planned to run for the Senate as a Democrat.

"I've been a liberal Republican, but I've always voted across party lines, supported [U.S. Rep.] Peter Welch, [U.S. Sen.] Patrick Leahy and others. Basically, the way the Republican Party is heading today does not reflect my views," he said. "It's become too partisan, too far to the right."

While Galbraith would not yet offer a direct endorsement, he appears to support Allbee's bid. The incumbent senator joined his Townsend neighbor at Brattleboro's Gallery Walk Friday evening as the latter collected signatures to win a place on the ballot.

Galbraith said that he looks forward to returning to the role of "citizen," but may one day seek a return to public office.

"Who knows what will happen in the future?" he said. "I'll continue to be engaged in public issues, so I'm not ruling anything out."