By Andy Metzger

State House News Service

BOSTON -- Attorney General Martha Coakley's entry into the governor's race puts her seat up for grabs for the first time in eight years, and could leave Auditor Suzanne Bump as Beacon Hill's lone elected statewide official running as an incumbent.

Secretary of State William Galvin, a Brighton Democrat who has held the office since 1995, has reportedly shown interest in seeking the state's top law-enforcement office, and Treasurer Steven Grossman is campaigning for governor, which means five of the state's six constitutional offices may be open next year. Galvin told the News Service this year only that he'd be on the 2014 ballot.

Coakley, who made an unsuccessful bid for U.S. Sen. Edward Kennedy's seat after his death in 2010, made official her candidacy for governor Monday.

"I think there are a number of good candidates" for attorney general, Senate Minority Leader Bruce Tarr, a Gloucester Republican, told the News Service, without specifying any. "I think what we're going to see is, certainly, an election cycle that's going to see a number of dominoes tumble, and create opportunities that I hope the Republican caucus and the Republican Party is prepared to take advantage of.

"I never say never," Tarr, who mulled a run for U.S. Senate earlier this year, said when asked whether he is considering a run for AG, though he said he is focused on trying to repeal the so-called tech tax.

Norfolk Rep. Dan Winslow, a Republican, former judge and chief legal counsel to Gov. Mitt Romney, convinced many he has aims on the seat, tweeting right after news of Coakley's intentions broke Sunday that he would make "an announcement regarding my future plans at 11 a.m. on Monday."

But at 11 a.m., Winslow announced his departure from the Legislature to become general counsel at Rimini Street, a major provider of software support services.

Unlike the other five constitutional offices, the attorney general carries with it the requirement in Massachusetts General Laws that it "shall be a member of the bar of the commonwealth."

The Legislature and other halls of government are filled with many attorneys.

The "most obvious" source of candidates could be district attorneys, a Democratic operative told the News Service, mentioning Bristol County District Attorney C. Sam Sutter and Essex DA Jonathan Blodgett.

Sutter has received recent press exposure as his office prosecutes former New England Patriots tight end Aaron Hernandez on charges of murder.

Suffolk District Attorney Dan Conley, a Democrat who handles one of the most high-profile prosecutorial offices in the state, is in the midst of a campaign for mayor of Boston, though some have speculated he would be in a prime position to seek AG if his mayoral bid fails.

Middlesex County Sheriff Peter Koutoujian, and Sens. Will Brownsberger and Katherine Clark, all Democrats running for Congress in a special election this fall, have also been mentioned as potential AG contenders.

Clark, a Melrose resident who was previously policy-division chief in the AG's Office, won the endorsement of Coakley in her congressional bid.

Koutoujian, a Waltham resident and former Middlesex County prosecutor, was a House lawmaker before his midterm appointment by Gov. Deval Patrick to oversee jails and houses of corrections in the state's most populace county.

Brownsberger is a former prosecutor and defense attorney.

James McKenna, who won the 2010 Republican nomination for attorney general in a write-in campaign, said "absolutely no" when asked Monday if he's going to run again, though he said "it was a lot of fun."

Salem Mayor Kim Driscoll and Somerville Mayor Joe Curtatone, who have both considered statewide runs, are attorneys, as is Scott Lang, the former mayor of New Bedford, who is thinking about a run for public office, according to the operative.

New Bedford Mayor Jonathan Mitchell is a former assistant U.S. attorney who worked on the search for mobster and former FBI informant James "Whitey" Bulger. 

Rep. David Linsky, a Democrat who served as a Middlesex Country prosecutor has also come up in discussions of potential AG candidates.

The Democratic operative mentioned Warren Tolman, a former state senator and representative who was the Democratic nominee for lieutenant governor in 1998 alongside then-Attorney General Scott Harshbarger, as a potential candidate for the office.

Newburyport Rep. Michael Costello, a Democrat who is a co-chairman of the Committee on Financial Services, would be a good candidate, the Democrat said.

A different person who follows government and politics said Dean Richlin, an attorney at Foley Hoag who was the first assistant attorney general to Attorney General Tom Reilly, could be a candidate.

In 2006, Coakley faced no primary opposition and went on to trounce Republican Larry Frisoli in the general election for attorney general.

Both of Coakley's immediate predecessors, Reilly and Harshbarger, mounted unsuccessful campaigns for governor. Harshbarger beat Attorney General James Shannon in the 1990 Democratic primary.