Fairfax County School Board candidate Karen Keys-Gamarra won the election for an at-large seat. (Keys-Gamarra Campaign)

Fairfax County voters elected a candidate backed by the Democratic Party to the school board Tuesday in a special election that was cast as a test of the party’s strength in the Northern Virginia county.

Karen Keys-Gamarra, an attorney and child advocate, won the at-large seat with 41,519 votes.

Chris Grisafe, a federal contractor endorsed by the Fairfax County Republican Committee, received 21,389 votes. A little more than 70,000 people cast ballots, putting turnout at about 10 percent.

Keys-Gamarra will fill the seat of Jeanette Hough, who left the board in June after her husband’s job took the family overseas. Hough, who held the at-large seat on the 12-member board, was elected in 2015 with an endorsement from the Fairfax County Republican Committee and was one of three GOP-backed members.

The board is officially nonpartisan, but candidates are often elected with endorsements and money from the local Democratic and Republican party committees. In recent years, the Democratic- and Republican-backed factions of the board have been fiercely divided over many issues, including how to accommodate transgender students, sexual education curriculum and whether to strip the names of Confederate figures from schools.

The board in 2015 voted to teach students about transgender issues in sex ed and to include transgender students and staff in its nondiscrimination policy. Both moves were opposed by conservative parents and the GOP-endorsed board members. In July, the board voted to rename J.E.B. Stuart High following a contentious, two-year process that led to heated community forums. The board’s two GOP-backed members dissented. Stuart was a Confederate Army general.

Those issues played an outsized role in this election, with Keys-Gamarra and her opponent staking out opposite positions. Keys-Gamarra said she backed the board’s decision to rename J.E.B. Stuart High, while Grisafe assailed the board for not seeking enough community input. Keys-Gamarra also said transgender students should be able to use bathrooms matching their gender identity. Grisafe said transgender students should use unisex restrooms to avoid making their classmates feel uncomfortable.

Keys-Gamarra said she hopes she can bring more harmony to the board and to school politics.

“I’d like to bring healthy community discussions because I think the tenor of some of those discussions in the past has been far too divisive,” she said. “They have marginalized students, they have marginalized members of our community.”

Keys-Gamarra, the mother of three Fairfax County schools graduates, received substantial financial backing from the Democratic Party, which donated more than $60,000 to her effort. Grisafe raised about $25,000.

State party leaders celebrated the news, drawing parallels between Keys-Gamarra’s win and that of Jackie Smith, a Democrat who defeated a powerful Republican this year to become clerk of courts in Prince William County, a populous swing county. Democratic strategists pointed out she prevailed even in districts represented by Republican state lawmakers.

“Karen Keys-Gamarra’s victory tonight reinforces what Jackie Smith’s win proved in April: Democrats are energized and organized, and we’re coming out to in droves,” Susan Swecker, chairwoman of the Virginia Democratic Party, said in a statement.

Grisafe disagreed, saying his loss should not be taken as evidence the party has weakened. The party’s efforts in his race could help lay a foundation for a GOP victory in November’s governor’s race, he said. He attributed his loss to being outspent by his opponent.

“What I’ve seen in the last couple of weeks is the Fairfax County Republican Party and the state party . . . coming together and coalescing like we haven’t before,” Grisafe said. “I do believe that we are much better postured through this effort going into the November election.”