Alison Friedman, one of six Democrats running for the nomination to challenge Rep. Barbara Comstock in Virginia's 10th Congressional District, speaks alongside the other five candidates at a forum in Haymarket on April 10. From left to right are Jennifer Wexton, Julia Biggins, Friedman, Lindsey Davis Stover, Dan Helmer and Paul Pelletier. (Jahi Chikwendiu/The Washington Post)

A pair of the six Democratic candidates vying to challenge incumbent Rep. Barbara Comstock (R-Va) in a pivotal Northern Virginia district turned their rhetorical fire Sunday on the establishment favorite between bouts of attacking Republicans and President Trump.

Army veteran Dan Helmer renewed his attack on state Sen. Jennifer T. Wexton (Loudoun) over her support for a 2016 legislative compromise that expanded the rights of concealed-carry gun permit holders in Virginia and across the country.

Lindsey Davis Stover, who worked on veterans policy as a senior adviser in the Obama administration, joined in, saying Wexton’s vote was “reckless and shows bad judgment.”

The gun law, which was opposed by gun-control advocates, allowed concealed-carry reciprocity but also forced domestic abusers to relinquish their firearms and allowed voluntary background checks at gun shows.

Wexton said the legislation, the result of a deal between then-Gov. Terry McAuliffe (D), GOP leaders and the National Rifle Association, has helped victims of domestic violence because the law made possession of a gun a felony by someone named in a protective order.

“I do not support nationwide concealed carry,” said Wexton, the only candidate in the Democratic field who has held public office. “This is what you do when you govern. You compromise.”

Wexton, a two-term state senator with the strongest name recognition in the Democratic field, has been endorsed by leading Democrats, including Gov. Ralph Northam and Reps. Gerald E. Connolly and A. Donald McEachin.

Helmer also attacked Wexton for accepting corporate PAC donations, including money from Dominion Energy, the state’s largest utility and biggest corporate political donor.

Wexton later dismissed Helmer’s assertions.

“I haven’t taken any PAC money in this election, and I’ve already pledged not to take Dominion money,” she said. She acknowledged accepting those contributions during her state Senate races but added that “if that’s supposed to influence my voting, it’s not working too well” as she cited her votes against the interests of the energy giant.

According to federal campaign filings, Wexton has accepted $5,000 in contributions from three non-corporate political action committees: $2,000 from the Turkish Coalition Midwest PAC, $1,000 from Commonwealth PAC and $1,000 from the International Union of Painters and Allied Trades Action PAC. Helmer has received $7,700 in non-corporate political action committees: $5,000 from Vets Vote, $1,700 from JStreet and $1,000 from National Security Democrats.

Helmer doubled down on his criticism after the forum.

“Almost $200,000 over the course of her career came from the same donors who gave to Comstock,” he said

Most of the two-hour discussion at Colvin Run Elementary School in Vienna, however, focused heavily on why voters should dump Comstock in November’s general election and resist Trump’s initiatives.

The forum, which was moderated by Washington Post Fact-Checker columnist Glenn Kessler, was sponsored by the Dranesville District Democratic Committee. About 300 Democrats turned out for the event, and the audience applauded attacks on Trump and Comstock.

But first, they must choose a party nominee in the June 12 primary.

The Democrats focused on Comstock’s “A” rating from the NRA, which is headquartered in Fairfax County, and her support of the Republican tax bill that they excoriated as a giveaway to the wealthy and corporations at the expense of working and middle-class people.

They differed on how to improve Obamacare — whether to replace it with an option for Medicare for all, as Helmer advocated, or a single-payer system, as scientist Julia Biggins said.

Alison Friedman, a former Obama administration State Department official and anti-human-trafficking activist, also attacked the Republican Congress for its failure to address gun violence and stand up to the Trump administration.

Former federal prosecutor Paul Pelletier, another hopeful, warned that the nominee needs to be able to appeal across party lines.

Comstock has built up a commanding reserve of cash this year, with $1.8 million in her coffers. Among Democrats, Friedman reported almost $818,000 followed by Wexton, with $630,707 on hand by March 31.

Virginia’s sprawling 10th Congressional District includes all of Loudoun County and parts of Fairfax and Prince William counties, as well as all of Frederick and Clarke counties to the west.

Both parties consider it one of the most competitive seats in the country — the Cook Political Report characterizes it as a “toss-up” — because President Trump is unpopular with the suburban women who represent a significant voting bloc there. Hillary Clinton won the district by 10 percentage points, but Comstock outperformed Trump by 16 points and sailed to reelection in 2016.

The “blue wave” last November that swept a dozen Democratic Virginia legislators into office over mostly incumbent Republicans is worrisome to GOP activists, and the record number of resignations or retirements of GOP House members from across the country, including Comstock’s friend, House Speaker Paul D. Ryan (R-Wis.), also warns of a potentially difficult November for Republicans.