Liam CurranFive Democrats will vie for the 13th Suffolk House seat left open after Savin Hill lawmaker Marty Walsh took the top job at City Hall. The candidates, according to Secretary of State William Galvin’s office, are Liam Curran of Coffey Street, Gene Gorman of Hooper Street, Daniel Hunt of Pierce Avenue, PJ McCann of Savin Hill Avenue, and John O’Toole of 114 Minot St.

There are no Republicans on the ballot, meaning that whoever wins the March 4 Democratic primary will likely coast through the April 1 general special election.

Gene GormanTony Dang, a MBTA police officer who is active in the Vietnamese-American community, is running a write-in campaign. Dang is a Democrat, though he did not enroll in the party until after the deadline for doing so in the special election.

O’Toole is the only candidate who has previously run for public office in Dorchester. He was on the ballot for the District 3 Council seat in 2011, losing to Frank Baker. TDan Hunthe rest are newcomers: Hunt has served as a government affairs liaison at the Department of Conservation and Recreation; Curran and McCann are lawyers; and Gorman is a member of a group of activists who worked to keep open the Roger Clap School in Columbia/Savin Hill.

Labor organizations could have a sizable impact on the race if they choose to wade in. O’Toole is a member of Plumbers and Gasfitters Local 12, while Curran, a labor lawyer, once worked in the general counsel’s office of the Laborers’ International Union of North America.

PJ McCannWalsh, who occupied the 13th Suffolk seat for 16 years, was a longtime labor leader and briefly served as head of the building trades union. He is publicly staying out of the race.

The Greater Boston Labor Council has been interviewing candidates, and if the council signs off on an endorsement of a candidate, it will forward the name to the state’s AFL-CIO, an umbrella group of unions. The endorsement hurdle is high for a prospective candidate, however: To get the nod, he will need support from two-thirds of the organization’s board.

John O'TooleThe March 4 primary will likely be a low-wattage affair, mirroring the 1997 special election that Walsh won. Jim Brett, who ran for mayor in 1993 and lost to Thomas Menino, stepped down from the 13th Suffolk seat, prompting a six-way race to replace him, with many of the candidates hailing from the Neponset neighborhood, including Walsh; future Attorney General Martha Coakley; James Hunt III, Dan Hunt’s brother; Charles Tevnan; Edward Regal; and Charles Burke.

In a March 11 primary, Walsh captured 2,085 votes, while Hunt picked up 1,839. Coakley ended up in fourth place with 746 votes. There were 6,430 votes cast, and no Republicans on the ballot. Walsh breezed into the seat in the general election, which drew 886 voters to the polls.

The district is currently made up of Columbia/Savin Hill, part of Codman Square, Clam Point, Port Norfolk, Neponset and a precinct in North Quincy.