Comstock — the establishment favorite who has worked for years in Republican politics — won with about 54 percent of the vote, according to unofficial results released by 10th District Republican committee, which conducted the election. The former Wolf aide and political consultant beat out five other contenders for the nomination, despite the lower-turnout nominating process that could have caused an upset.

“It is an honor and a privilege to win my party’s nomination for Virginia’s 10th Congressional District and follow in the footsteps of my mentor, Congressman Frank Wolf,” Comstock said in a statement. “Now is the time for all Republicans to unite and pool our resources together to defend this seat from Nancy Pelosi’s hand-picked candidate.”

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Republican voters had only 10 polling places – instead of the 187 in a normal election — to cast their ballot within a five-hour window.

Comstock’s cash advantage helped her build a strong ground game to overcome the potential for an upset. As of April 6, Comstock had spent about $240,000 — more than 16 times as much as Bob Marshall, who was seen as Comstock’s biggest threat in getting the nomination and ended up in second place with 28 percent of the vote. Comstock still had more than $520,000 in the bank in early April and will go into the general election already well-funded.

Virginia’s 10th congressional district — which stretches from McLean west to Winchester in Northern Virginia – is a top target for Democrats and is expected to see tons of outside spending from both sides. Mitt Romney carried the seat by just 1 point in 2012. Democrats had privately hoped the firehouse primary would cause one of the more socially-conservative, weaker general election candidates to win to have an easier path to victory in November.

But big-name endorsements from conservatives such as Mark Levin, Sean Hannity, Newt Gingrich and George and Susan Allen boosted Comstock’s bid for the nomination, despite attacks from her opponents, who targeted her for voting for Barack Obama in the 2008 Democratic primary, for being a Washington insider and for not being a true conservative.

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“Barbara’s message and record of common sense conservatism has resonated throughout the 10th District, where she has support from grass-roots activists and precinct captains, to dozens of elected officials in the 10th District,” Susan Falconer, Comstock’s campaign manager, said in an email before the primary.

Comstock will face Fairfax County Supervisor John Foust in the November general election.

Foust said in an interview earlier this week that his message of growth and opportunity would stand out, regardless of who his GOP opponent is.

“There’s not a lot of difference between the Republican candidates on issues, so it’s not going to make a difference,” he said.