All Tierney needs to do to win in this D+7 district is to repeatedly say that Tisei would be a loyal foot soldier for the far right leadership(Cantor and Boehner) that is currently in charge of Congress. Tisei will lose for the same reason that Torkildson lost in 1996 and 1998.
This isnt like 1992 when voters here could vote out an incumbent like Mavroules(who was actually indicted three weeks before the election) knowing that it wouldnt give more power to the far right Republican leadership.
The problem with your scenario is that Tisei is not an undefined quantity in this district. He's represented over a quarter of it for years in the state legislature, where he most certainly did not act as a loyal foot soldier of the GOP. He's an openly gay, pro-choice, liberal Republican. It's not a believable charge, and Tierney is not a believable enough to make that charge stick.
As soon as he gets to Congress, Boehner and Cantor will have him doing whatever they want. Also, the GOP leadership in Massachussetts had absolutely zero power with about 25% of the seats.
Bobby Bright was a known quantity in his Alabama district and was the hugely popular and conservative mayor of a city that made about about a fifth of the distirct. In 2008, his flawed opponent attacked him as a rubber stamp for Pelosi and came within a 1000 votes of beating him because of it. In an even slightly less toxic Republican environment, Bright would have lost.
If Tisei is an actual "liberal Republican", he would support the healthcare bill and letting the Bush tax cuts expire. Instead, hes talking about repealing healthcare.
