Virginia’s most socially conservative state lawmaker was ousted from office Tuesday by Danica Roem, a Democrat who will be one of the nation’s first openly transgender elected officials and who embodies much of what Del. Robert G. Marshall fought against in Richmond.

The race focused on traffic and other local issues in suburban Prince William County but also exposed the nation’s fault lines over gender identity. It pitted a 33-year-old former journalist who began her physical gender transition four years ago against a 13-term incumbent who called himself Virginia’s“chief homophobe” and earlier this year introduced a “bathroom bill” that died in committee.

“Discrimination is a disqualifier,” a jubilant Roem said Tuesday night as her margin of victory became clear. “This is about the people of the 13th District disregarding fear tactics, disregarding phobias . . . where we celebrate you because of who you are, not despite it.”

Marshall, 73, who refused to debate Roem and referred to her with male pronouns, declined an interview request but posted a concession message on Facebook.

“For 26 years I’ve been proud to fight for you, and fight for our future,” he said. “I’m committed to continue the fight for you, but in a different role going forward.”

Democrat Danica Roem, right, watches election results Tuesday night with Linda Daubert, left, of Indivisible NOVA West, at Grafton Street Restaurant and Bar in Gainesville, Va. (Jahi Chikwendiu/The Washington Post)

The contest was one of dozens of state legislative races in which Democrats pushed to gain ground in the Republican-majority General Assembly, buoyed by a surge of anti-Trump sentiment among Democrats and independents, and hoping to provide an example for the nation of how to run in opposition to the unpopular Republican president. It also was the most prominent of several elections across the country in which transgender individuals won seats on city councils and a school board.

[City council candidate is first openly transgender African American woman elected in the U.S.]

Roem outraised Marshall 3-to-1 with nearly $500,000 in donations, much of it coming from LGBT advocates and other supporters across the country. Her campaign was relentless, knocking on doors more than 75,000 times in a district with 52,471 registered voters. Roem sat for myriad public appearances and interviews and maintained a steady social media presence. Marshall kept his schedule private but also mounted a healthy ground game; his campaign said this week that staffers knocked on voters’ doors about 49,000 times this fall.

The race took an ugly turn when Marshall and his supporters produced ads disparaging Roem ’s transgender identity.

But in the end, that tactic failed. Roem led by nearly nine percentage points with all precincts reporting, according to preliminary, unofficial results. Advocates say she will be the first openly transgender person seated in a U.S. state legislature; a transgender candidate was elected in New Hampshire in 2012 but did not take office, and a transgender person served in the Massachusetts legislature in the early 1990s but was not openly transgender while campaigning.

“It’s kind of like Barack [Obama] winning the presidential election. I’m really proud of Virginia,” said Roem voter John Coughlin, 63, a Realtor in Manassas who said he had never voted for Marshall. “I don’t care about religious issues. I don’t care about items that are big on his agenda. He should be more mainstream.”

[See full Virginia election results]

Stephen J. Farnsworth, a political-science professor at the University of Mary Washington in Fredericksburg, said Roem’s victory shows “that cultural wars don’t win elections like they used to.”

“Virginia has changed so rapidly over the past 20 years. It’s gone from a state where no politician would dare to condemn the Confederacy to a state where a suburban district would elect a transgender candidate,” Farnsworth said. “The Old Dominion gives way to a very different New Dominion.”

In addition to calling Marshall “a mirror” of Trump, Roem accused him of being more concerned with advancing his conservative causes than dealing with local problems. That message resonated in communities along Route 28 — particularly Manassas Park, an area that has seen an influx of immigrants and millennials. Marshall lost there four years ago.

“I work in Tysons sometimes in the morning, and it can take up to two hours, and the main reason for that is Route 28,” said Miranda Jehle, 21, a Roem voter who lives in Manassas Park. “That issue definitely resonated here.”

Nat King, 50, called the congested thoroughfare “the one issue that I know has to be addressed.”

“That was the primary factor in how I voted,” said King, who lives in the Signal Hill area and cast his ballot for Roem. “Someone has to fix Route 28.”

[Danica Roem: A policy wonk in a rainbow head scarf]

Marshall emphasized his record of helping constituents with individual problems.

But he also countered Roem’s attacks with appeals to his conservative base, helped by last-minute donations from the state Republican Party and conservative groups outside Virginia that have long supported him.

A cable television ad by Marshall’s campaign questioned Roem’s moral judgment with brief footage from a five-year-old music video she appeared in with her band. A scene from the video, which did not appear fully in the ad, is suggestive of a group of people having oral sex.

A state Republican Party flier accused Roem of “wanting transgenderism taught to kindergartners” — a reference to a radio interview in which she supported the idea of addressing lesbian, gay, bisexual and transgender matters in schools “in an age-appropriate manner.”

Quentin Kidd, director of the Wason Center for Public Policy at Christopher Newport University, said Marshall may have erred in making too much of Roem’s gender while refusing to participate in public-policy debates.

“He got put in a box on a cultural war issue, and the irony is that he’s made his living on cultural war issues,” Kidd said.

[Del. Marshall: Conservative warrior fights to preserve ‘laws of nature’]

But some Marshall voters said they were turned off by Roem’s gender. “She’s never had menstrual cramps, and she’s never had a baby, and she never will be able to,” said Carol Fox, a community activist in the Heritage Hunt section of Prince William, where Roem campaigned repeatedly. “She can take all the estrogen she wants, but she’ll never be a woman.”

Alexis Dimouro, 53, who voted for Marshall, said she was turned off by negativity on both sides, including attacks on Roem’s gender and Roem’s characterization of Marshall as a conservative zealotout of touch with local issues.

“Let us do the research and decide,” she said. “All of that seemed like a waste of money.”

At the Water’s End Brewery in Lake Ridge, a crowd of supporters and news cameras awaited Roem as she drove in for a final stop in what became a victory tour of Prince William County Democratic parties.

The crowd chanted “Danica! Danica!” She raised her fist and shouted “Sí, se puede!”

Standing on a table inside the pub, Roem dedicated her win “to every person who’s ever been singled out, who’s ever been stigmatized, who’s ever been the misfit, who’s ever been the kid in the corner, who’s ever needed someone to stand up for them when they didn’t have a voice of their own. This one is for you.”

She then reiterated her promises of alleviating traffic congestion on Route 28.

“That’s why I got in this race,” Roem said. “Because I’m fed up with the frickin’ road over in my home town.”