Baker narrows list of running mates

Baker is hoping to choose a candidate for lieutenant governor this weekend and is considering Senate minority leader Richard R. Tisei of Wakefield, House minority leader Bradley H. Jones Jr. of North Reading, Plymouth District Attorney Timothy J. Cruz, and state Representative Karyn E. Polito of Shrewsbury.

Each candidate brings strengths and weaknesses that could help Baker balance his ticket and appeal to Democrats and independents.

Tisei, who is thought to be the leading candidate, is an only-in-Massachusetts character: a Republican leader who publicly disclosed yesterday that he is gay. Polito would add gender balance to the ticket, Cruz would bring a tough-on-crime image, and Jones brings geographic advantages because he comes from a part of Middlesex County that is rich in potential Republican votes.

By naming a running mate now, Baker is hoping to head off other Republicans from entering the lieutenant governor’s race, so he can conserve resources for the 2010 campaign. Baker and his lieutenant governor candidate could then both raise money, effectively doubling the amount Baker could raise on his own under campaign finance limits.

Although candidates for governor and lieutenant governor are not legally a ticket and do not appear so on party primary ballots, state campaign regulators, following a 1990 court case, have given wide leeway for candidates to run as a ticket in primaries.

Baker, the former chief executive of Harvard Pilgrim Health Care and a onetime head of two state agencies, has raised more than $1 million since he began fund-raising several months ago.

He is battling Christy Mihos, the Cape Cod-based convenience store owner and 2006 independent gubernatorial candidate who talks of spending some of his fortune in seeking the Republican nomination for governor. Mihos spent $4 million of his personal funds in 2006.

State Treasurer Timothy P. Cahill, a former Democrat, says he will run for governor as an independent. And the incumbent, Democrat Deval Patrick, plans to seek a second four-year term.

None of the candidates on Baker’s list of potential running mates are household names statewide, but they are well-known in Republican circles.

The best bet, according to campaign advisers familiar with the process, is that Baker will chose Tisei, whose time in the Legislature would provide balance for Baker, whose only experience in elective office was a stint as a Swampscott selectman. Tisei, 47, and Baker have known each other for years, and Tisei is Baker’s campaign chairman.

Tisei was first elected to the House at age 22 and moved to the Senate in 1991. His sexual orientation has been an open secret on Beacon Hill, and he disclosed it publicly yesterday in an interview with the Globe, anticipating the scrutiny that would accompany a statewide candidacy. “It is not exactly a news flash,’’ he said . “I don’t think people really care these days.’’

Cruz has built a high-profile reputation as a prosecutor in Plymouth County, one of the few strongholds of state Republicans. He is known for moderate views.

Jones has been a steady GOP opposition leader, but has faced an overwhelming Democratic House majority, which has made it hard for him to influence public policy. He has also had to deal with some GOP colleagues who feel he is too close to the Democratic leadership.

Polito, 43, has been open about her political ambition, and has displayed some political independence, including joining a failed effort to replace Jones as House minority leader last year.

Baker had been interested in tapping Cahill as a running mate, in part because early polls show Baker and Cahill dividing the anti-Patrick vote and giving the governor the best chance for reelection. But Cahill said earlier this month that he turned down overtures to join the ticket. According to state election laws, Cahill cannot qualify for the GOP primary because he has not been registered as a Republican.