Democratic Fairfax County Supervisor James Walkinshaw won the special election for Virginia’s 11th Congressional District, defeating Republican Stewart Whitson.

The Associated Press called the race at 7:36 p.m. Eastern time, confirming Walkinshaw’s decisive victory.

The seat was previously held by Democratic Rep. Gerry Connolly, who passed away in May after representing the district for over 15 years.

Before his death, Connolly endorsed Walkinshaw and his campaign transferred $1.8 million to a PAC supporting Walkinshaw in the primary, helping secure the Democratic nomination, Politico has reported.

Walkinshaw’s win in the Washington, D.C. suburbs strengthens the Democratic presence in Congress, posing additional challenges for Republicans managing a narrow majority and looming budget negotiations.