Controversial Virginia state Sen. Dick Black (R) will drop his bid for retiring Rep. Frank WolfFrank Rudolph WolfHouse votes to mandate sexual harassment training for members and staff Trump, global religious freedom needs US ambassador to lead Bottom Line MORE's (R-Va.) seat, two Virginia Republicans with knowledge of his decision told The Hill.

Black's decision potentially clears the way for Virginia Del. Barbara ComstockBarbara Jean ComstockThe GOP is Trump's party now House GOP frets over Pennsylvania race Giffords's group eyes Ryan, other high-profile Republicans ahead of midterms MORE (R) to avoid a contentious battle for the nomination and is a relief to national Republicans who fretted he could be the nominee.

The state senator says Virginia Republicans' loss of a special state senate election earlier this week prompted his decision to pull out of the race.

"Our nation and Virginia are at a critical juncture," Black said in statement emailed to The Hill late Wednesday night. "I seriously considered running for the 10th Congressional seat, however, after meeting with Republican Caucus leaders in Richmond, it is imperative that I remain in the Senate where I am needed to maintain our 20/20 split."

Black has stirred controversy in the past by his actions and comments on social issues. He has in the past compared abortion clinics to Auschwitz, and during a legislative debate on an abortion law, he passed out plastic fetuses.

Comstock, a top Republican lawyer, former Wolf staffer and lobbyist, has been racking up endorsements from across the party. She has the backing of Mitt Romney, who she worked for in 2012, as well as conservative radio host Mark Levin and Americans for Prosperity President Tim Phillips.

Comstock might still have a battle for the nomination on her hands, though Virginia Republicans say Black posed the biggest threat to her in a convention battle because of his fervent following. Local Republican Party heads will determine whether the party will have an open primary, a "Firehouse primary" run by the party, or a party convention in a Thursday evening meeting, and a number of potential candidates are waiting to see what the party decides before making their own decisions on the race.

Democrats are hopeful they can compete for the seat in the slightly Republican-leaning Northern Virginia district. National Republicans think Comstock would be tough to beat, however, and were much more worried about a crowded field producing a flawed nominee.

"Republicans just breathed big sigh of relief with this news. Makes our chances of holding this expensive open seat a lot easier," said one national GOP strategist focused on House races.

— Updated at 12:05 a.m.