From right, Pinar Gurdal, Rick Shingles and Russell Chisholm show their opposition to the Mountain Valley Pipeline project during the debate for the Democratic nomination for governor at Virginia Western Community College on Thursday, May 4, 2017, in Roanoke, Va. Lt. Gov. Ralph Northam and former congressman Tom Perriello both claimed Thursday to be Virginia Democrats' best option for winning over rural voters who supported President Donald Trump in last year's election. (Heather Rousseau/AP)

ROANOKE -- Gas pipelines are a touchy subject in this mountainous part of the state, and Lt. Gov. Ralph Northam struggled to find the right thing to say about two proposed projects Thursday night during a debate with his rival for the Democratic gubernatorial nomination.

Emotions regarding the pipelines run high in the region. Supporters say the projects will generate jobs; opponents say they will harm the environment and property rights. And the sponsor of one pipeline, Dominion Energy, is a major political donor whose largesse has come under fire this election season.

Northam, who has received campaign cash from Dominion and owns stock in the company, repeatedly declined to stake out a position Thursday on the multibillion dollar Atlantic Coast and Mountain Valley pipelines, which would bring fracked gas from West Virginia through Virginia.

Former Congressman Tom Perriello, who is challenging Northam for the nomination, is opposed to the projects and sought to underline that fact, as well as his pledge not to accept campaign donations from Dominion.

[Power broker in hot seat in governor’s race]

Lt. Gov. Ralph Northam, left, and former congressman Tom Perriello, who are seeking the Democratic nomination for governor in the June 13 primary election, debate at Virginia Western Community College on Thursday, May 4, 2017, in Roanoke, Va. (Heather Rousseau/AP)

But there were other flareups in the second debate between Northam and Perriello that highlighted a fundamental difference between two candidates who tend to agree on most issues.

Simply put, Northam stressed his ability to compromise with the Republican-controlled General Assembly and spoke about modest ways of attacking problems that might win support across the aisle. And Perriello talked about aggressive goals and big ideas that won cheers from the crowd.

Where Northam talked about encouraging economic development and workplace training to help the under-employed find better jobs, Perriello promoted his plan for free community college and mandatory 8-week paid family leave.

Northam outlined his own proposal for tuition-free community college that would be followed by a year of paid community service, much as he paid off his government-funded medical training by serving as an Army doctor for eight years.

But Perriello countered that such a plan is unrealistic for working people who just need a chance at a better career path and don’t need the distraction of community service. When Northam responded that Perriello’s plan, which includes tax increases, would be too expensive to pass the General Assembly, the polite affair began to heat up.

“Community service would be more expensive, not less expensive,” Perriello interrupted. “How would that pay for the plan?”

“Did me serving for eight years in the United States Army make it more expensive, Tom?” Northam snapped back.

Perriello replied that he honored the military service, but that a community service program would carry extra public costs. That seemed to further irritate Northam.

“So you’re telling me that people like me shouldn’t serve in the United States Army…” he said, and the crowd began to groan and drown him out.

“I think you just lost the audience, doctor,” Perriello said.

“No I didn’t,” Northam shot back.

The awkwardexchange spun into a dustup a few minutes later when the topic of pipelines came up.

A small but vocal group of pipeline opponents in an audience of at least 250 people at Virginia Western Community College interrupted Northam several times as he repeatedly declined to say whether he supported or was opposed to two major gas pipeline projects now under review.

Asked by the moderator for his stand, Northam first described efforts he has taken to protect the state’s environment on other issues. Then he said that if the pipelines move forward, they need to be done with “transparency and fairness,” and with sensitivity to property rights. And he described how he wrote a letter to the state Department of Environmental Quality insisting that permits be determined on a site-specific basis, rather than a blanket approval.

But the decision is ultimately up to the federal government about whether they proceed, he said.

That opened the door for Perriello to step up and say, “I do oppose the two pipelines and I’m the only person on this stage to refuse to take any money from Dominion Power and the other electric utilities.”

In addition to Perriello, 61 Democratic candidates for the state legislature have also pledged not to take campaign contributions from Dominion.

The moderator, WDBJ news anchor Jean Jadhon, again pressed Northam: “Can you say yes or no?”

“You know I think I explained my position on the pipelines….” Northam began, and some in the crowd interrupted, one woman shouting, “Aw, come on.”

“It’s not something a governor or lieutenant governor can make the decision on,” Northam continued.

After that, the two candidates mounted no more harsh personal challenges. In fact, Northam didn’t challenge Perriello on his changing position on issues of gun control and abortion rights. At other times Northam has highlighted that Perriello won top ratings from the NRA in his time in Congress and voted for an amendment that would have restricted federal funding for abortions.

[Shades of blue in the Democratic primary for Va. governor]

Asked how they would woo voters in rural parts of the state who had supported President Trump, Northam responded that he has won in rural areas before because “I went out and listened to people and heard what they were saying.” He touted his plans for education, health care and “21st century jobs” training.

Perriello sounded similar notes. “You show up, you listen, then you have to have something to say,” he said. But then he added a bigger thought: “People feel like the system has been rigged against certain regions...because it has been.”

On the same day that the GOP-controlled House voted to replace the Affordable Care Act, both men lamented the vote in Congress and vowed to fight Washington. But when asked how they could actually get anything done with a General Assembly that’s likely to remain under Republican control, their answers highlighted different approaches.

Northam invoked his 10 years in the legislature, first as a state senator, and cited his ability to compromise with Republicans. Perriello invoked his experience working in Africa for the Obama administration, saying they could use a “peace negotiator” in Richmond, as well.

The two are campaigning toward a June 13 primary. Three Republicans are vying for that party’s nomination, though their names never came up in Thursday’s debate: former Republican National Committee chairman Ed Gillespie, state Sen. Frank Wagner (Virginia Beach) and Prince William County Board of Supervisors Chairman Corey Stewart.