Democrats have found a powerful new attack in one of the most symbolically important races in the country.

State Del. Barbara Comstock, running to replace Republican Rep. Frank Wolf in the Virginia exurbs of Washington, D.C., has benefited from her deep connections to national Republican political operatives, which date back to her time as a congressional investigator digging into Clinton White House scandals. But now those connections are coming back to bite her, after it was revealed that she pushed bills in the state legislature while being paid by an advocacy group that wanted those bills passed.

Comstock shepherded three bills to curtail union rights in Virginia between 2011 and 2013 while being paid as a consultant for the Workforce Fairness Institute, a right-to-work advocacy group that listed the bills among its legislative priorities, Politico reported last week. That revelation came after The Washington Post reported that Comstock failed to report tens of thousands of dollars in income, including at least $5,000 from Workforce Fairness Institute.

Democrats are going all in on the news, saying Comstock intentionally obfuscated the payment.

Her Democratic opponent, Fairfax County Supervisor John Foust, launched a new ad this weekend alleging that Comstock “hid” her work for the group, and others have piled on. “Barbara Comstock has been caught using her position as a delegate in order to push through priorities of her paying clients – a truly disturbing breach of our trust. Even worse, she didn’t disclose it,” Foust said in a statement. “Comstock’s actions are frankly inexcusable, and are further proof that she can’t be trusted to speak for Northern Virginians in Congress.”

Legal experts have said it’s unclear if Comstock violated Virginia’s notoriously lax campaign finance laws. But Scott Surovell, the chair of the state House Democratic Caucus, said Comstock should have recused herself from legislation impacting her clients. “As a part-time legislator many of us have jobs apart from our duties as members of the House of Delegates, but that is why it is imperative that we disclose and abstain from votes when it is in our personal interest,” he said in a statement. “Delegate Comstock not only voted on legislation that directly benefited her company, but she introduced the legislation herself.”

The Comstock campaign defended the candidate, saying she did everything required by Virginia law. “John Foust’s false ad is just one more negative attack because he has no issues to run on except his long record of raising our taxes,” campaign manager Susan Falconer told msnbc in a statement. “It is no secret that Barbara Comstock has worked in a public and open fashion – on TV, radio, and in print – advocating right to work policies. John Foust is just shilling for his union boss cronies who got him to oppose Delegate Comstock’s right to work and competitive bidding legislation even though it has saved taxpayers $400 million dollars.”

The campaign arms of both House Democrats and Republicans have scaled back their ad buying in the district, leading both sides to express confidence in a tossup district that leans slightly Republican. President Obama won the district in by three percentage points in 2008, but lost it by just one in 2012.

Democrats say the lack of outside spending will keep the focus on the candidates, which they think is good news for their side. But in an election year that favors Republicans overall, most prognosticators think the race leans Republican. That’s why Democrats are doubling down on the ethics allegation, hoping the “October surprise” can shift the race.

The race has attracted unusual attention from national political players on both sides of the aisle. Bold-name Republicans like Karl Rove, Newt Gingrich and former Mississippi Gov. Haley Barbour have donated to Comstock’s campaign, while Clinton-aligned Democrats have done what they can to prevent Comstock from coming back to Washington.

“I won’t go into too much detail about Comstock’s record, but let’s just say she’s a professional Clinton hater,” Clinton political aide Paul Begala said in a fundraising email for Foust last week.

During the Clinton administration, Comstock was a tenacious and feared investigator working for Republicans on a congressional committee that was looking into Clinton White House scandals.

And Democrats warn that if she wins, she’ll use her perch in Congress to attack a Hillary Clinton presidency. An ad from a Democratic super PAC said Comstock was “hell bent on smearing Hillary Clinton.” The House Majority PAC ad encouraged viewers to “stand with Hillary” by stopping Comstock.

For such a nationalized race, the ethics issue is a surprisingly local one. Whether voters care, however, remains to be seen.