Del. Robert G. Marshall R-Prince William) speaks during a meeting of the Virginia House’s Courts of Justice Committee in 2012. (Bob Brown/Richmond Times-Dispatch/Associated Press)

Virginia Del. Robert G. Marshall likes to compare himself to a World War II Marine — storming the beach and taking bullets as he tries to advance his conservative cause.

Now, the 13-term Republican incumbent is facing what could be his toughest reelection battle, with Democrats gunning hard for his seat this November as part of their strategy to cut into the Republican majority in the House of Delegates and launch what they hope will be a national resurgence for their party following the election of President Trump.

Marshall's opponent, Danica Roem, would be the state's first elected official who is openly transgender, an identity that the incumbent describes as "against the laws of nature and nature's God."

Moreover, she is attacking both Marshall's conservative social agenda and his effectiveness in dealing with local district problems.

In other words, Marshall, 73, is in his element.

“Help me protect conservative values in Virginia!” Marshall says in a campaign flier seeking donations. “My defeat would signal that holding these principles is a detriment to being elected.”

A Roman Catholic who entered politics as an antiabortion activist, Marshall describes himself as on a crusade to uphold both Christian beliefs and the principles of the nation’s Founding Fathers.

He is known in his Prince William County district for caring deeply about traffic and other local issues, fighting against any proposed tax increase and showing up frequently at community and civic meetings and events, often wearing a rumpled suit.

In Richmond, he has elicited groans even from fellow Republicans while introducing bills to declare pornography a public health hazard, warn women who join the National Guard that they may see active military duty or, year after year, declare that the 1973 Roe v. Wade Supreme Court decision legalizing abortion nationwide is based on false science and that life begins at conception.

Marshall presents a “parenthood” bill during a meeting of lawmakers in Richmond in 2012. (Steve Helber/Associated Press)

His failed efforts to regulate which bathrooms transgender people can use and require ­anti-discrimination policies in schools to "recognize the inherent differences between males and females" helped motivate Roem to run against him.

“I think, for the most part, people appreciate that I don’t beat around the bush,” Marshall said. “Had I measured the odds of winning, I probably would not have done some of the things I have done.”

Conservative worldview

Marshall grew up a Democrat in suburban Montgomery County, Md. As a teenager, he drove John F. Kennedy voters to the polls. He cast a ballot for Hubert H. Humphrey in 1968. But the seeds of his conservative worldview were already growing.

While a student at Montgomery College, he came across a library book that struck a deep chord. “Witness,” by Whittaker Chambers, is both a retelling of the case against accused Soviet spy Alger Hiss and a political treatise that became a foundation for today’s conservative movement, casting the world in the stark Cold War-era terms of good vs. evil.

That viewpoint stayed with Marshall as he studied history and philosophy at Belmont Abbey College in North Carolina and earned a master’s degree in humanities from California State University at Dominguez Hills. He abandoned plans to become a U.S. Marine fighter pilot after failing the vision test.

In 1969, an effort to relax abortion laws in Maryland triggered what for Marshall would become a lifelong fight against pregnancy terminations. He met his wife, Cathy, at an antiabortion organization meeting in 1974.

Marshall lost his first political race when he ran as an independent for a seat in Maryland’s House of Delegates. He soon aligned with the Republican Party, joining the staff of U.S. Rep. Robert K. Dornan (R-Calif.), a conservative firebrand who later helped Marshall find work for antiabortion groups. The Family Research Council, for which Marshall worked as a research consultant for nearly a decade, is now one of his top political donors, giving $5,000 to his current campaign.

Marshall and his wife, Cathy, address the Virginia Rally for Life in Richmond in 2011. (Bob Brown/Richmond Times-Dispatch/Associated Press)

By the early 1990s, Marshall was director for family life affairs at the Catholic Diocese of Arlington. He and Cathy were raising five children, three of them adopted, in Prince William, a Virginia exurb 36 miles southwest of Washington.

The state’s 13th District had just been redrawn, leaving an open seat. Marshall ran and won, beating a Democrat who attacked his conservatism while Marshall insisted that voters cared more about the area’s growing traffic problems.

He has been reelected 12 times, facing a challenger in all but one of those contests. The only candidate who came close to beating him was Democrat Atif M. Qarni, who lost in 2013 by 498 votes, out of 17,429 votes cast.

‘One-man band’

As a state lawmaker, Marshall quickly became a voice of dissent on the fringe of Virginia’s button-down Republican Party.

He led an unsuccessful fight to keep former TV anchor Hugh Finn on life support after Finn suffered severe brain damage in a car accident, turning the battle into a moral indictment of state laws governing end-of-life issues.

Then Marshall's family experienced a tragedy of its own: His son Christopher, 19, was fatally injured when the pickup truck he was riding in crashed into a tractor-trailer stopped on the shoulder of Interstate 81. Two years later, Marshall pushed through a law that requires commercial trucks to use emergency flashers or triangular reflectors when stopped on a roadway. He calls his son's death "a devastating loss, something I would not wish on my worst enemy."

In 2008, Marshall successfully sued the state over a new transportation-funding law, which was popular in Northern Virginia because it gave regional transportation authorities $1.1 billion per year in taxing power to fund road projects.

Marshall saw a flaw in the law because the members of those boards aren’t elected. The Virginia Supreme Court unanimously agreed, nullifying the statute in a ruling that said the state constitution gives taxing authority only to elected officials.

“He was like a one-man band, and, initially, everybody said: ‘Oh, that’s just Bob Marshall,’ ” recalled Bob Holsworth, a former Virginia Commonwealth University ­political-science professor. “But it turned out he was right.”

Marshall announces his bid for the Republican nomination for U.S. Senate in 2008, alongside his son Tommy, and wife, Cathy, right. He lost at a state party convention, and lost in a Republican primary when he again sought his party’s Senate nomination four years later. (Steve Helber/Associated Press)

Marshall also opposed Virginia’s current transportation funding law, which uses state tax revenue.

In the most recent legislative session, Marshall introduced 30 bills. Two passed. One arranged for interim appointments for school board members called to military duty. The other celebrated the life of Sen. Charles J. Colgan (D), who died in January.

The veteran lawmaker lists on his campaign website 23 issues he hopes to tackle in future sessions, including abortion, religious liberty and fighting tolls on Interstate 66.

Low-profile campaign

On a recent day, after talking to voters, Marshall sat in the front row at a meeting of the Northern Virginia Transportation Authority inside the Manassas Park Community Center.

The event was meant to gauge residents’ reactions to four proposals to address traffic congestion along Route 28. Roem was also there, talking up her plan to use $300 million in state money to get rid of traffic lights along the highway.

Marshall, who wants to create reversible lanes on Route 28, kept a low profile at the meeting, as he has for much of his reelection campaign. He has asked reporters to email him questions in advance instead of sitting for interviews and refused to allow The Washington Post to accompany him when he goes out to meet voters.

Marshall speaks at the state capitol in Richmond in 2014. (Bob Brown/Richmond Times-Dispatch/Associated Press)

His wife's recent bout with cancer, now in remission, kept him from campaigning earlier this year, Marshall said. And vocal opposition from some of Roem's supporters — including name-calling — has made him unwilling to appear on stage with her face-to-face.

At the transportation meeting, Marshall raised his hand once, to ask if the cost of either widening Route 28 or building a new road extension factored in the need to also widen an existing bridge on the state roadway.

The answer was yes.

The query gave Marshall a chance to play a favorite role: that of a watchdog sniffing for potential wrongdoing.

“Most elected officials don’t want to get into the details,” Barbara Daymude, 72, an undecided voter, said approvingly.

About a month earlier, Marshall showed up to support a group of African American residents fighting plans by the Dominion Energy utility company to build power lines in their community.

Marshall has been a thorn in the company’s side, introducing several bills to further regulate how and where new power lines can be installed. None have passed, however. And his conservative stances on other topics have alienated some of the same residents and local activists who have welcomed his presence in the Dominion fight.

“He drives me crazy, sometimes,” said Elena Schlossberg, director of the Coalition to Protect Prince William County. Still, she conceded: “Bob has a way of advocating for local issues that matter to people. He shows up to meetings, and people who might not vote for Bob might wind up voting for Bob.”

Marshall has received $132,000 in campaign donations this year, $80,000 of it in September and $20,000 coming from the chairman of a conservative think tank in Washington that, among other things, opposes protections for transgender individuals.

During a recent radio interview, Marshall called the election part of a moral battle to preserve “the laws of nature.”

“Danica is clearly out here doing this to make a mark on the national character,” Marshall said. “That you can engage in this kind of behavior — which clearly goes against the laws of nature and nature’s God — and hold public office and make decisions on behalf of the common good. That is what is at stake here with the moral question.”

Fenit Nirappil contributed to this report.