Democrats in West Cambridge “take their politics very seriously,” according to Ward 9 Committee Chairperson Helen Glikman. On Monday night, Glikman noted the “nice energy” inside Cambridge's Tobin School as the four candidates — Julia Fahey, Jonathan Hecht, Stephen Corbett, and Joshua Weisbuch — all vying for the vacant 29th Middlesex state representative seat, debated in front of a crowd of Cambridge and Watertown residents. The candidate forum, organized by members of Cambridge’s Democratic City Committee, presented the state rep hopefuls with discussion topics from health care and education to turnpike tolls and civil rights. “This is the beginning of the conversation about the end,” said Ward 9 committee member Andrea Kramer, who moderated the meeting. The State House seat has been open since June, after longtime Watertown incumbent Rachel Kaprielian left to become the registrar of motor vehicles. Since then, all four Democratic candidates from Watertown have been hitting the pavement in Kaprielian’s former district — that includes Watertown and Ward 9 in Cambridge — making a grassroots effort with residents who plan to cast their write-in or sticker vote in the September primary. To win the nomination, a candidate must get a minimum of 150 write-in/sticker votes during the primary. The candidate with the most votes in each party would win the nomination and make the statewide November ballot, according to the Secretary of Stat ...