Tierney tried to portray Tisei, an openly gay former state legislator who favors abortion rights, as a tea party extremist. He repeatedly noted that Tisei would caucus with the Republicans and help further a GOP agenda that is out of step with the Boston-area district. A vote for Tisei, he said, was "a vote for keeping this right-wing Congress in power."
Tisei presented himself as a pragmatic centrist and an ""independent-minded legislator."
He bristled as the suggestion that he is an extremist. "I'm the only person in the entire United States running for office right now who supports gay marriage, who is pro-choice, who wouldn't sign the Norquist tax pledge that's being attacked for being extreme, [a] tea party extremist, " he said. "It just doesn't make any sense."
The race is one of the Republican Party's top targets, both because it is a potential pick-up and a chance for a symbolic victory in the Northeast. Speaker John Boehner was in town earlier in the week to help Tisei raise money for the campaign's final push.
Despite the backing from the national GOP, Tisei tried to present himself as a bipartisan politician. Asked about his proudest moment in politics, he cited a "Democrats for Tisei" campaign event when former Democratic colleagues in the state Legislature endorsed him. "It just made me feel so good," he said.
Tisei tried to paint Tierney as a purely partisan foot solider. "His history is voting 99 percent of the time with the [Democratic] leadership," he said. He ticked off Tierney's poor ratings from a litany of business groups, including the U.S. Chamber of Commerce, the retailers association, and the small business association.
"All the wings of the Republican party, essentially," Tierney replied. Being rated poorly by such groups is "not a problem for anyone who wants to create jobs," he said. When Tierney went on to declare that "people in business aren't worried about being over-regulated," a smattering of boos came from the crowd.
Despite the fact that the issue has flooded the airwaves and voter mailboxes, Tisei didn't focus on the allegations surrounding Tierney and his wife. For some supporters, it was cause for disgruntlement. "You're too nice," Dave Rose, an independent voter backing Tisei, told him in the parking lot after the debate. "That's your problem."
Tisei said in a post-debate interview that he expected the issue would arise in a future face-to-face encounter.
"No, it didn't come up," he said, "but I expect that it will."