Congress has tackled a lot of big issues in the past four years, from health-care reform and the debt ceiling to wars and the Arab Spring. What Rep. Gerald E. Connolly considers his own biggest achievements in that time may seem mundane by comparison, but you wouldn’t know it as he ticked them off.

“Telework,” the Virginia Democrat declared enthusiastically, referring to a bill he introduced to encourage government employees to work from home. With equal gusto, he explained the importance of his efforts to beef up the Federal Acquisition Institute, improve the experiences of government interns and make federal jobs more flexible and desirable.

You have to know who you work for, Connolly says, and you have to be realistic about what you can accomplish.

The latter lesson is one that Connolly, who is expected to win a third term in November, has learned well since he was first elected to Congress in 2008. Before representing Virginia’s 11th District, which includes parts of Fairfax and Prince William counties — and is home to more federal workers and contractors than almost any other district in the nation — he served 14 years as a Fairfax County supervisor, including five as the board’s chairman.

In what is essentially the most powerful position in county government, he earned a reputation as an effective strongman who got things done. He admits that leaving that post to be freshman in the House — one ruled by Republicans, to boot — took some adjustment.

“As chairman, you set the agenda, and I set a very aggressive one,” he said in a recent interview. “On the Hill, you can carve out a niche . . . but you never set the agenda. You’re one of 535.”

Connolly last race was close — he prevailed by fewer than 1,000 votes — but he is widely expected to win again, in large part because the district has been redrawn to be more favorable to Democrats. He is facing Republican Chris Perkins, a retired Army colonel who has never held elected office.

A former Green Beret who left the military after 24 years in 2006, Perkins has called Connolly a career politician who is “interested in being something rather than doing something.” The challenger says Connolly’s vote for budget sequestration amounted to putting his party ahead of his constituents, and he contends that the biggest difference between them is their views of the proper role and size of government.

“I think at the federal level, we have lost our way,” Perkins said.

If Connolly is worried, he isn’t showing it. He dismisses Perkins as unqualified, based on what he calls his failure since leaving the Army to become civically engaged in the 11th District.

“What do you think it means when people say that all politics is local?” he said.

By most accounts, Connolly, 62, has made the transition to Congress effectively, in part because of his experience as a Senate staffer before he was a county supervisor. As for niches, he’s forged a few, including his efforts related to the federal workforce — an area he considers crucial for his district’s unique economy — and foreign policy. He serves on the House Foreign Affairs and the Oversight and Government Reform committees.

On foreign policy matters, Connolly has “gained traction because when he talks, he actually knows something,” said Norman Ornstein of the American Enterprise Institute. Connolly worked on the Senate Foreign Relations Committee staff for 10 years.

As a legislator, Ornstein called Connolly “solid” and “savvy.” Among his successes are the telework bill, which expanded the practice among federal employees; legislation to improve federal internship programs in order to recruit more highly skilled workers; a bill that bolstered training and oversight of federal acquisitions workers to stem waste and fraud in contracting; an amendment that mandated the use of fuel-efficient tents among frontline troops, meant to reduce the need for fuel convoys and therefore deaths among soldiers guarding them; and a recent executive order that strengthens protections against international human trafficking by federal subcontractors.

Colleagues from both parties have praised Connolly for working with Republicans. Although he has voted with Democrats most of the time, he has gone against his party in some cases, including his support last year for free-trade agreements with Panama, South Korea and Colombia.

Rep. Chris Van Hollen (D-Md.) said Connolly, who spent six years in a seminary before going to Harvard, studies issues with wonkish enthusiasm, deciding positions for himself rather than reflexively toeing a party line.

“He challenges members of all political backgrounds,” Van Hollen said.

It’s something that Connolly, a Boston native, wishes there was more of; he said the exacting, humorless partisanship of federal politics has been an especially tough adjustment. “In local government,” he said, “you’d never freeze out the minority.”

“It’s the most accountable level of government,” he said of his time with Fairfax County. “Either you got the sidewalk built or you didn’t.”