U.S. Rep. Mike Thompson (D-Calif.) and shooting survivor and former representative Gabrielle Giffords (D-Ariz.) hold a news conference about Thompson’s proposed gun background check legislation on Capitol Hill in Washington Feb. 26, 2019. (Jonathan Ernst/Reuters)

The gun-control group headed by former congresswoman Gabrielle Giffords plans to endorse Democrats in two key Republican-held districts in Virginia on Friday, part of an effort to help the party regain control of the General Assembly in the fall.

The Giffords group said it will support Dan Helmer in his Fairfax County race against Del. Tim Hugo (R-Fairfax), and Del. John Bell (D-Loudoun) in his bid to fill retiring Republican Sen. Richard H. Black’s Loudoun County seat.

Peter Ambler, director of the group created by Giffords (D-Ariz.) and her husband Mark Kelly after she survived a 2011 assassination attempt by a gunman, said the organization also plans to become involved in other General Assembly races.

All 140 seats in the state Senate and House of Delegates are on the ballot in November, when Virginia will be the only U.S. state in which the parties are in a competitive fight for control of the legislature.

A Democratic majority in both chambers would allow gun-control advocates to pass legislation mandating universal background checks and other restrictions, Ambler said. The GOP, which maintains a razor-thin majority in both houses, killed dozens of gun-safety bills in the legislative session that ended last month.

“Not only does getting these folks into the majority give us what we need to pass lifesaving legislation, it gives them a mandate to do that,” Ambler said.

Ambler said his group’s political action committee — which last year spent $1 million on behalf of Rep. Jennifer Wexton (D-Va.) in her successful bid to unseat former Rep. Barbara Comstock (R-Va.) — remains undecided on whether it will give financial support to the candidates in Virginia.

But Giffords is to appear Sunday in McLean at a joint fundraiser for Helmer and Bell, he said.

The extra muscle comes as Democrats seek to recover from the scandals over blackface involving Gov. Ralph Northam (D) and Attorney General Mark R. Herring (D), and sexual assault allegations against Lt. Gov. Justin Fairfax (D).

Before their three top statewide officeholders were embroiled in controversy, Democrats appeared poised to continue a wave of victories in recent years that has put them three seats away from a majority in the House of Delegates and two seats away in the Senate.

Republicans plan to highlight the problems in the executive branch. But recent news about mass shootings in New Zealand, Aurora, Ill. and elsewhere could convince voters that gun reforms are more urgent, especially in increasingly blue Northern Virginia.

Helmer, who last year highlighted lax gun laws in Virginia while unsuccessfully seeking his party’s nomination for Wexton’s seat, is working to flip the area’s last remaining Republican state House seat, which encompasses portions of Fairfax and Prince William counties

The former U.S. Army major wants to limit handgun purchases to one per month, impose stricter background checks and limit the size of magazines that can be bought for semiautomatic guns.

Hugo, who is seeking his eighth term, has supported concealed-carry legislation and allowing guns in bars and restaurants.

In Black’s soon-to-be open state Senate district, which straddles Loudoun and Prince William counties, Bell is also pushing for universal background checks.

The former U.S. Air Force major is competing in the June 11 primary against two other Democrats who also support stricter gun-control laws: financial adviser Lucero Wiley and activist Jasmine Moawad-Barrientos.

The Republicans seeking to replace Black are: Ex-CIA operations officer Mike Buscher and Loudoun County Supervisors Ron A. Meyer Jr. (R-Broad Run) and Geary M. Higgins (R-Catoctin).

Ambler said Helmer and Bell have articulated the strongest positions on gun safety, adding that their military background “gives them unimpeachable credibility” on the issue.

Pro-gun groups are also ramping up their plans for the fall elections. John Fenter, chairman of the political action committee of the Virginia Citizens Defense League organization, said his organization plans to be “as aggressive as we can afford” in supporting favored candidates.

The gun debate “is always prominent,” he said. “There’s a group of people that don’t believe in the right to bear arms, and there’s a group of people that do.”

An earlier version of this story incorrectly included former White House technology adviser Suhas Subramanyam and former U.S. Marine Kyle Green among those competing in the Democratic primary to seek the seat being vacated by Sen. Richard H. Black (R). They are no longer in the race. This story has been updated.