If past elections indicate anything, the Middle sex and Suffolk Senate seat is the most volatile in the Cambridge area. While every other race in recent memory has ended with the Democratic primary, an Independent coped this office in the 1980 November election, upsetting a long-time Democratic incumbent.

George Bachrach, who pulled off a stunning victory two years ago, re-entered the Democratic party this year and handily beat three challengers. But, taking the lessons of his own campaign two years ago to heart, he is not letting his guard down for the November election because he faces Republican businesswoman Marta Batmasian.

"We are running a full-fledged campaign. We have a campaign office going. We have a campaign staff going. I'll be back at the shopping centers and the MBTA stops soon." Bachrach says.

He has, since the primary ended, gotten the support of his three defeated challenger. The size of his victory also scared off an independent who, while still on the ballot, has dropped from active participation in the race.

In addition to the party machinery, Bachrach has a diligent record of constituent service behind him. Since taking over the office, he has held regular office hours around the district, and maintained an efficient response system in his office.

The district includes Belmost, Watertown, parts of Boston, a North Cambridge.

But Batmasian says that field work notwithstanding. Bachrach is out of touch with the district.

The incumbent senator has clearly staked out a liberal position for himself in what is widely considered a conservative area. He has taken the lead in the legislature for the nuclear freeze and against the death penalty. He has also taken a progressive position on economic proposals, supporting, for example, a graduate income tax.

David Geller, Batmastan's recently-tapped campaign manager, says Bachrach has emphasized issues that are irrelevant to many of his constituents. Batmasian plans to stress economic issues, and her comparatively conservative positions, he says

Batmasian, a local real estate agent, says that her private sector experience will help her act responsible in state government "He [Bachrach] doesn't know the private sector because he's never been there," she says

Other factors that may work in the Republican's favor are Batmastan't Armenian name and trace of a foreign accent. As an Armenian running in what includes heavily Armenian sections of Water town, she may benefit from an ethnic crossover.