State Rep. Marie St. Fleur isn’t running for re-election, a move that opens up the Fifth Suffolk District seat for the first time in a decade. St. Fleur’s retirement is the second in the last month within the Dorchester and Mattapan community, with state Rep. Willie Mae Allen also announcing she is not running for reelection.

At a caucus of Ward 15 Democrats, St. Fleur, a self-described “Uphams Corner kid,” made clear the job that she has held for over a decade was no longer for her. “I don’t want to be in the way of anyone,” she said. “The job can’t be done half-hearted.” The first Haitian-American elected to the Legislature, St. Fleur noted that she has one daughter in college, another “on her way,” and a son about to start high school. “So it’s time for transitions,” she said.

Those who know St. Fleur, who was sent to the Consumer Protection Committee as punishment for not taking a side in last year’s battle for the House speakership, say that she has grown miserable on Beacon Hill and has been itching to leave. During the U.S. Senate election, she told Democratic Party officials that she was interested in replacing U.S. Rep. Michael Capuano, who lost the Democratic primary to Attorney General Martha Coakley in December. It was the latest in a string of jobs she has expressed interest in over the last several years.

“Government is stuck right now” and needs “young people to elbow some of the old folks out,” St. Fleur told Ward 15 activists and elected politicians on Saturday, including Congressmen Michael Capuano and Stephen Lynch, state Rep. Marty Walsh, and former state Rep. Charlotte Golar Richie, who recruited St. Fleur to run for the seat after Golar Richie stepped down.

Alix Cantave, associate director of the Trotter Institute at UMass-Boston and an adviser to St. Fleur, said collegiality at the State House has declined. “The mood on Beacon Hill is part of it,” he said. “I think it’s taken a toll on her. It’s not a very healthy place right now.”

The field of potential candidates who have expressed interest in replacing St. Fleur includes Carlos Henriquez, a community activist who has twice unsuccessfully run against District 7 Councillor Chuck Turner; Barry Lawton, a high school teacher and Democratic State Committee member who challenged St. Fleur unsuccessfully in the 1999 special election; unenrolled candidate Steve Wise; and perennial candidates Althea Garrison and Roy Owens.

Both Lawton and Henriquez appeared at Saturday’s caucus at Savin Hill Apartments. Lawton had his two children in tow and wearing “Barry Lawton for State Representative” buttons.

But some influential party activists are eyeing other candidates. “We’re looking for a winner,” said Judy Meredith, a former chair of the Ward 15 Democratic Committee. “They’re all fine people. But they’ve run before and they’ve lost before.”

The small but powerful cadre of activists in the Ward 15 and Ward 13 Democratic Committees will likely play a big role in deciding who St. Fleur’s replacement will be, given history. When Garrison, running as a Republican, knocked then-state Rep. Nelson Merced off the Democratic ballot in 1992 by successfully challenging him on an electoral technicality, some of the Fifth Suffolk activists sought to recruit someone to challenge Garrison. The result was Golar Richie, who did just that in 1994. The same group helped recruit St. Fleur for the seat in 1999.

Names that have come up in discussions among local party activists include John Barros, who was recently appointed to the Boston School Committee; Karen Charles, acting chief of staff at the Massachusetts Bay Transportation Authority (MBTA); and Candace Sealey, Capuano’s liaison in Mattapan, Dorchester, Roxbury and Hyde Park.

But both Barros and Charles say they are focused on their current jobs. “I am honored that people in the district feel that I would be a good candidate to represent them in the Legislature,” said Charles, “ but at this time, I can tell you that I am unequivocally not a candidate for the seat.” Barros, who is also head of the Dudley St. Neighborhood Initiative, said “at this point, I’m excited” to work on Boston Public Schools. Sealey could not be reached for comment by press time.

“Greatest Minds,” a group of young black Bostonians that put together several forums during the race for City Council At-Large last year, is hosting a discussion on the pair of open House seats and potential candidates to replace St. Fleur and Allen. The forum is scheduled for March 1 at the National Black College Alliance in Roxbury’s Dudley Square at 6:30 p.m.

St. Fleur has held a variety of posts within the Legislature, including vice chair of the budget-writing House Ways and Means Committee and co-chair of the Education Committee. She was also briefly a candidate for lieutenant governor on a joint ticket with gubernatorial candidate Thomas Reilly in 2006, until media reports of financial problems forced her to withdraw.

During her caucus remarks, St. Fleur turned to a reporter and said, “No...I don’t have a job,” an apparent reference to the rampant rumors that she has a position lined up within Mayor Thomas Menino’s administration. Menino and St. Fleur are said to be close friends, and St. Fleur was a tenacious campaigner for Menino during his re-election fight last year.

There has also been talk about her taking a state or national post dealing with recovery efforts for Haiti, which in January was ravaged by an earthquake. St. Fleur is friendly with Patrick Gaspard, the White House’s political director and the Obama administration’s highest-ranking Haitian-American, and she was among the first people he reached out to when the earthquake hit Haiti.

Alix Cantave said he could see St. Fleur becoming a liaison between the Haitian-American community and the Haitian government. “I think she’s such an asset to the Haitian community,” he said. Cantave will take the stage with St. Fleur on Friday to talk about how Haiti is faring more than a month after the earthquake. The talk is scheduled for 6 p.m. in Lipke Auditorium at UMass-Boston. “Wherever she goes, she’ll do well,” Cantave added. “She’s committed, she’s hardworking.”

“I think Marie has been really energetic, a forceful, compassionate leader,” Golar Richie said. “She has persevered and really met our expectations, those of staying focused on the issues and working hard to make sure resources and services are delivered to the district.” Added Barros: “In keeping with the really incredible string of leaders we’ve had, Marie has upheld that legacy and improved upon it.”

At the caucus, St. Fleur said she was proud of several accomplishments during her ten-year tenure, including the creation of the Department of Early Education and Care and protecting aspects of bilingual education. Indeed, St. Fleur supporters have pointed to speeches she has given in support of gay marriage, or a fiery speech she gave in July 2003 on the House floor in support of bilingual education, in which she easily switched between English, French, and French-Creole.

“I thank you from the bottom of my heart,” she told Ward 15 party activists. “I won’t be a stranger,” she promised.