LOWELL — In a civil debate that turned on gentle differences of policy and biography, US Representatives Edward J. Markey and Stephen F. Lynch sought to showcase their blue-collar roots and argued over gay rights and outside spending in their race for the Democratic Senate nomination.
Markey, of Malden, and Lynch, of South Boston, avoided direct and hostile confrontations during the 45-minute forum at the University of Massachusetts Lowell on Monday night.
Instead, facing each other with just three weeks remaining before the April 30 primary, they charged through a range of issues, from areas where they believe they could work with Republicans to their views on the use of drones by the American military.
If anything, Markey, though he is leading in the polls, took the more aggressive posture, going after Lynch, as he has in the past, for voting against President Obama’s health care law and in support of the across-the-board cuts known as sequestration, two issues bound to resonate with core Democratic voters.
Lynch made clear his differences with Markey by arguing that Washington already has too many “elite and privileged individuals” and needs someone like him, a former ironworker who grew up in public housing. “I’m not saying that every US senator should have stood in an unemployment line; I’m not saying that every US senator should have struggled through night school to get a degree,” Lynch said. “I’m just saying one US senator, one US senator should have had that experience.”
Throughout the race, Lynch has emphasized his humble beginnings, but Markey seemed determined Monday night not to be outdone in the biographical battle. He recounted a visit a few years ago to the childhood home of his father, in Lawrence, “in the shadow of the mills.”
Markey said he rang the doorbell on the first floor and found a Dominican family there. “The accents were different, but the aspirations clearly the same,” he said. “They want, for their children, what the Markeys were able to receive living in that triple-decker.”
The debate was the second of four and was streamed live on the website of The Boston Herald, a sponsor, but was not shown on television and did not produce any explosive moments that could upend the dynamic of the contest.
When the debate turned to the involvement of outside interests, Lynch took the opportunity to pounce on Thomas F. Steyer, a Democrat and California hedge-fund billionaire, who has spent $400,000 on planes with banners, door-to-door canvassers, and trucks with video screens criticizing Lynch for refusing to oppose the Keystone XL oil pipeline from Canada. Lynch believes the pipeline could create construction jobs while Steyer, like Markey, believes it will commit the United States to dirty oil from Canadian tar sands.
Lynch said he was not threatened by Steyer’s attacks.
“I faced bullies my whole life,” Lynch said, “and I wouldn’t put up with that.”
Markey reiterated his objection to Steyer’s involvement in the race, even though he stands to benefit from Steyer’s attacks on his rival. “On day one, I said to Mr. Steyer, stay out of our state,” Markey said.
As the two continued to squabble over the Keystone pipeline, Markey was pressed by the moderator, former television reporter Jaclyn Cashman, to explain how he can oppose the pipeline even though he is backed by Larry Rasky, a veteran Democratic strategist who has been hired by the government of Alberta, Canada, to promote the pipeline.
After sidestepping the question one time, Markey said that “everyone is free to have their own positions,” on the pipeline, but “the only person whose name is on the ballot is mine.”
On social issues, both candidates said they support same-sex marriage. Lynch, who was seen by gay rights activists as a strong opponent of domestic partnership legislation and other gay rights bills during his time in the Legislature in the 1990s, also offered a mea culpa of sorts, saying, “If I voted to interfere with that, I was wrong.”
Markey faced no such tension on the question of gay rights, pointing out that he was one of just 62 House members to vote against the Defense of Marriage Act in 1996. It was just one example of an advantage Markey has battling Lynch on liberal territory in the Democratic primary.
Lynch and Markey took slightly different tacks when asked to name two areas where they could find common ground with Mitch McConnell, the Senate Republican leader from Kentucky. Markey, who has been criticized by Lynch for marching in lockstep with Democratic leaders and failing to reach across the aisle, said he could work with McConnell to expand broadband access to rural states and to improve veterans’ services.
Lynch, who has been criticized by Markey for siding too frequently with Republicans, took pains to say he could hardly think of two areas where he agrees with McConnell. Like Markey, he said that veterans’ services was one area, but then struggled to come up with a second. “I went through my checklist and there’s not a whole lot there I agree with him on,” Lynch said, before saying, “maybe on some transportation issues.”
Later in the debate, Markey sought to underscore his ability to agree with Republicans when he declared that he supported Senator Rand Paul’s recent filibuster to demand information from the Obama administration about its policy on drone strikes. “I agreed with Rand Paul,” Markey said. “The American people . . . have a right to answers.”
Joshua Miller of the Globe staff contributed to this report. Michael Levenson can be reached at mlevenson@