It was the first and last race she lost and it was here in Dorchester: State Attorney General Martha Coakley, now running for the U.S. Senate seat, finished fourth in a 1997 Democratic primary to replace state Rep. Jim Brett, who had retired.

“It was interesting,” she told the Reporter after losing to union activist Marty Walsh. “I got the sense I was everybody’s second choice. I’m not disappointed at all. I really intend to stay plugged into Dorchester. I had a great time running. I would do it again tomorrow. I feel like the community accepted me, at least as an adopted child.”

Twelve years later, Coakley lives in Medford and is the frontrunner in the race to succeed the late U.S. Sen. Edward Kennedy. She left Dorchester soon after the 1997 special election and was elected Middlesex County District Attorney in 1998.

How much support she has retained in Dorchester is unclear, though she has the backing of at least one former rival from 1997, the attorney Charles Tevnan. In the signature-gathering phase of the Senate race, her former neighbors in Pope’s Hill could be seen collecting names for her.

But most local activists and elected officials appear to be breaking for one of her three Democratic opponents, Congressman Michael Capuano (D-Somerville). And in a race where the Democratic primary is almost two months away, the endorsements – and the list of potential supporters that comes with each endorsement – could prove key.

With Congressman Stephen Lynch, whose district includes half of Dorchester while Capuano’s area includes the other half, out of the picture, local politicians are quickly lining up behind Capuano. Unions have also been taking sides.

A group calling itself “Dot for Capuano” has sprung up to organize standouts, phone banking, and polling station coverage during the Nov. 3 mayoral race as well as the Dec. 8 preliminary election. The group includes state Rep. Walsh, who had supported Lynch before he dropped out of the race, state Sen. Jack Hart, state Rep. Linda Dorcena Forry, state Rep. Marie St. Fleur, state Rep. Willie Mae Allen, District 3 Councillor Maureen Feeney, Codman Square Health Center co-founder Bill Walczak, and well-known human services advocate and lobbyist Judy Meredith, among others.

State Sen. Sonia Chang-Diaz, whose Second Suffolk District includes a sliver of Dorchester, is undecided.

Other Democratic candidates running for the Senate seat are Boston Celtics co-owner Stephen Pagliuca and nonprofit activist Alan Khazei. Republicans include state Sen. Scott Brown (R-Wrentham) and Canton selectman Robert Burr. Several independents, including a Joseph Kennedy who is no relation to the Kennedy family member named Joseph who decided not to throw his hat in the ring.

Joyce Linehan, the head of the local public relations firm Ashmont Media, is among the “Dot for Capuano” organizers. A former Feeney staffer, Justin Holmes, is also involved in the group, as is Catherine O’Neill, a longtime local political hand.

Feeney’s endorsement of Capuano likely didn’t go over well with state Senate President Therese Murray, a top Coakley backer. Feeney and Murray, who was born in Dorchester, are close. And both were avid backers of Hillary Clinton’s bid for the presidency.

“We can’t afford have a U.S. senator who can take three or four years to learn how to do the job,” said Walsh. “[Capuano’s] the guy, I think, who can deliver.”

Dorchesterites also credit Capuano for helping to keep Caritas Carney Hospital open several years ago when it was in danger of closing due to a precarious financial position. (And some are still sore over a report Coakley’s office issued in 2008 on the future of Carney that suggested that the hospital consider shifting from being an acute care facility to one that focuses more on behavioral health, such as psychiatry and substance abuse treatment.)

“He stepped up to the plate and stuck with us since Day One,” Walsh said. “If it weren’t for efforts of Mike, who knows where we’d be with Carney Hospital.”

An e-mail blasted out by the group to drum up support listed Capuano’s positions on the issues, including that he “stood with Ted Kennedy against the war in Iraq.” “He strongly advocates a public option in healthcare reform,” they wrote. “He led the fight in Washington for ethics reform. He supports equal marriage, a woman’s right to choose, and tax cuts for the middle class.”

But some Dorchester residents remember Coakley’s 1997 run and say they were impressed enough to be supporting her for the U.S. Senate bid. “I think she presented herself quite well,” said Charlie Gillen, who supported Jim Hunt, Mayor Thomas Menino’s current chief of environmental and energy services, when he ran in the 1997 race. “I’ve watched her career. Every step of the way, I think she’s proven herself as a leader.”

Charlie Tevnan is backing his former rival. “She was highly qualified, an impressive candidate and an impressive speaker,” he remembers. Added another local Coakley backer, who requested anonymity because he was not authorized to express support: “My expectation is that there will be many, many supporters of Martha Coakley. They most likely will not be political people. They’ll be the mothers of the soccer players, the teachers, people who were exposed to her during her representative campaign many, many years ago.”

She also has the support of Dan Cullinane, who left Feeney’s office to work on the campaign. Cullinane handled communications work in Feeney’s office, and had also worked in the attorney general’s office and as an aide to Rep. Walsh.

In 1997, Coakley drew scattered support throughout the district, and finished with 716 votes, out of 6,333 total votes cast. Walsh received 2,085. And ads that ran during the race touted her as a “longtime Dorchester homeowner and taxpayer.”

But there is no mention of Dorchester or the 1997 race in her official biography on her campaign website. After she was elected Middlesex District Attorney, she spent eight years in the office, in which the bio says she “established herself as a passionate advocate for public safety, not only bringing justice to crime victims and their families, but also emphasizing the importance of working with community leaders, schools, and law enforcement in a variety of diverse and multifaceted prevention efforts.”

She was elected attorney general in 2006.

Her Senate campaign did not respond to a request for comment for this article.