It’s tough to knock off an incumbent, says the conventional wisdom of politics.

An incumbent is one thing. A 30-year congressman from Virginia’s 10th District, spanning as close as 15 miles outside the nation’s capital, is another beast altogether.

Kristin Cabral, a Democrat, and Kevin Chisholm, an Independent, have accepted the challenge; the two are squaring off against Republican Frank Wolf, the longest current-serving member of Congress from Virginia.

Cabral and Wolf are set to debate twice in late October; Chisholm says he’s continuing to push for an invitation from the event hosts.

Redrawn since Wolf’s early days, Virginia’s 10th Congressional District currently includes Loudoun, Clarke and Frederick counties, the cities of Manassas, Manassas Park and Winchester, and large portions of Fairfax and Prince William counties.

Frank Wolf

Wolf was first elected a U.S. Representative the same year Ronald Reagan won the presidency, 1980. In the past 25 years, he’s routinely won reelection by a 20-25 percent margin.

Much of Wolf’s championed legislation has focused on transportation, domestic and foreign security, and human rights. A member of the House Committee on Appropriations, Wolf is considered a rank-and-file Republican, according to govtrack.us. He also sits on the Subcommittee on Commerce, Justice, Science and Related Agencies – which he chairs – and the Subcommittee on Transportation, Housing and Urban Development and Related Agencies.

On issues specific to Loudoun County, Wolf has lobbied and advanced bills for greater oversight of the oft-maligned Metropolitan Washington Airports Authority, the organization overseeing the Dulles Corridor Metrorail Project, and proposed a study to consider dropping the tolls along the privately owned Dulles Greenway.

This year Wolf proposed the formation of a Congressional panel to study the mission of the war in Afghanistan. Wolf wants to pin down precisely what thousands of American troops are aiming for in Afghanistan and if it’s a valid use of the nation’s resources.

Wolf published a book in 2012, “Prisoner of Conscience,” in which he details various trips to Third World nations struggling with apartheid and repression. Global human and religious rights continues to be an issue Wolf speaks passionately on.

“I’m hoping to get people interested,” Wolf said in an interview discussing his memoir. “There are people still being tortured, people being persecuted for their religious beliefs.”

Human rights has always been a bipartisan issue, Wolf noted, but it’s been diminishing in importance and, like nearly everything in Washington, has become more political.

Kristin Cabral

Cabral, who has never held an elected political office, says she’s running for Congress because she’s “frustrated by partisan gridlock in Washington.”

“I’m not a politician,” she said. “I’m just a hardworking mom and professional who knows how to solve problems.”

Cabral has practiced law as a federal prosecutor within each of the three branches of the federal government. She was the first woman in her family to attend college, which she paid her way through with loans, scholarships, grants and by working various jobs.

“To this day, many families across the district are doing what I did to access a college education,” she said.

The Democrat has focused her campaign on trusting women, returning more tax dollars to the 10th District and claims that Wolf is “out of touch.”

Cabral points to Wolf’s reluctance for government funding to Planned Parenthood and his vote against the Lily Ledbetter Fair Pay Act as issues – specifically issues critical to women – in which her and the congressman disagree.

On transportation funding, Cabral criticizes Wolf for failing to bring in federal dollars for Phase Two of the Dulles Corridor Metrorail Project, also called Dulles rail.

Cabral says she’s looking to preserve the “American dream through educational opportunities and job opportunities.”

The Democrat notes her experience in volunteerism, including serving on the Fairfax County library board and various parent-teacher associations.

“I’m very much into creative thinking and outside-the-box thinking in order for us to move forward in the future,” Cabral said.

Cabral was a student at Harvard Law School during President Barack Obama’s enrollment at the school.

Kevin Chisholm

An engineer by trade and three-decade resident of Northern Virginia, Chisholm too said he’s running for Congress because he’s “frustrated with its inaction.”

“And that includes Mr. Wolf,” Chisholm said. “Incumbency is a huge problem with our Congress. We get people who are just really good self-promoters and don’t do what’s best for their district.”

A 55-year-old who previously ran for the Arlington County Board as a member of the Green Party, Chisholm listed reducing the federal deficit, drawing down our foreign military presence and developing a more secure energy policy as the central points of his campaign.

“I want to see the Federal government put on a long term, steady diet to restore America’s fiscal health,” Chisholm writes on his campaign website. “Having lived in this town for 30 years, I can give testimony to the inefficiencies and wastefulness of government. It starts with many overpaid, under-performing bureaucrats and includes employees that just don’t perform.”

Chisholm labels himself a “fiscally conservative progressive” and a “Jeffersonian.” He said issues dealing with transportation, roads and infrastructure are best left to state and local officials.