WASHINGTON — Karen A. Keys-Gamarra, who was endorsed by the Fairfax County Democratic Party, won a special election Tuesday to fill an at-large spot on the county school board.

Keys-Gamarra, an attorney and child advocate, earned 41,519 votes in the special election, according to online election returns posted by the Fairfax County Board of Elections.

That was nearly double the 21,389 votes cast for Republican-backed Chris S. Grisafe.

Sandra D. Allen received 719 votes. Michael H. Ownens received 1,346.

Only about 10 percent of the more than 677,000 active registered voters in Fairfax County voted in the special election.

Keys-Gamarra succeeds Jeanette Hough, who resigned her term early. The term lasts until Dec. 31, 2019.

In a statement, Virginia Democratic Party Chairwoman Susan Swecker praised Keys-Gamarra as “the candidate with the best understanding of the complex challenges facing the school system” and said she would address bullying and inclusive learning.

Voters in Virginia go back to the polls in November to decide statewide races for governor, lieutenant governor, attorney general and other offices.