By Aruna Viswanatha
Updated Feb. 13, 2018 2:57 p.m. ET
Chris Hunter was preparing to take a health-care fraud case to trial when he says he became concerned about the dynamics at the Justice Department, the agency where he had worked for more than a decade.
After watching President Donald Trump fire former FBI Director James Comey, belittle Attorney General Jeff Sessions, and pardon Sheriff Joe Arpaio, among other events, Mr. Hunter said he decided to leave his job as a prosecutor in Tampa in December and run for Congress.
Mr. Hunter is now one of at least six former federal prosecutors who are running for House seats as Democrats this year, compared with zero in 2016. The Wall Street Journal found one such Republican candidate.
“If Jeb Bush had been the [presidential] nominee and won, no way would I have run,” said Mr. Hunter, who also served as an FBI agent for three years after the Sept. 11 attacks. He is running in Florida’s 12th Congressional District, which Mr. Trump won by 19 percentage points and is a seat currently held by six-term Republican Gus Bilirakis.
A Bilirakis spokesman didn’t respond to a request for comment, but the congressman recently supported disclosing a Republican memo that he said described “highly disturbing” allegations of abuses by the Justice Department in the surveillance of a onetime Trump campaign aide.
The Washington landscape has been dominated this year by special counsel Robert Mueller’s investigation of Russian meddling in the 2016 election, and accompanying attacks on the Justice Department’s credibility. One result has been the spectacle of several federal prosecutors quitting to run for Congress.
The phenomenon reflects a broad frustration within the department, several of these candidates say. Current and former officials describe an agency with poor morale whose employees are trying to keep their heads down, continue working on cases and ignore the daily news cycle.
Republicans reject the idea that the crop of former prosecutors running as Democrats has a wider significance. “Voters on both sides of the aisle respect prosecutors and law-enforcement officers—they just do,” said Rep. Trey Gowdy (R., S.C.) himself a former prosecutor who is retiring from Congress.
Several Republican prosecutors won seats during the Obama administration, he said, part of a cycle that comes with any change in party control of the White House.
One such Republican, Clare Pozos, joined the race this month for Pennsylvania’s 7th Congressional District, and a Democratic ex-prosecutor, Ashley Lunkenheimer, is vying for the Democratic nomination in the same district. Republicans currently hold a 238-193 advantage in the House, with four vacancies.
The Justice Department has been buffeted by particularly forceful political winds of late. House Republicans earlier this month released a memo alleging abuses by the FBI and Justice Department when they sought an October 2016 application to monitor former Trump campaign adviser Carter Page who had been on the radar of U.S. intelligence since 2013, when alleged Russian spies made an attempt to recruit him.
After the memo’s release, Mr. Sessions said he had “great confidence in the men and women” of the Justice Department, adding that “no department is perfect.”
The memo prompted an unusual statement by the FBI Special Agents Association saying that agents “have not, and will not, allow partisan politics to distract us from our solemn commitment to our mission.”
Similar complaints from former federal prosecutors have spilled into Democratic primaries usually dominated by concerns like health-care and immigration.
At a packed forum Saturday for Democrats vying to unseat Republican Rep. Barbara Comstock in Virginia’s 10th district, seven candidates introduced themselves. Amid questions on economic and social issues, one candidate presented himself as a former federal prosecutor of 27 years who could take on Mr. Trump.
Ms. Comstock “sits silently each and every day as the president and this Republican Congress denigrate and impugn the integrity of federal law enforcement, the same men and women who protect us every single day,” said the candidate, Paul Pelletier.
A spokesman for Ms. Comstock, who herself worked as a public-affairs official at the Justice Department during the George W. Bush administration, said she “has been a strong advocate for her former colleagues at Justice and the FBI.”
Among the top Democratic recruits is Conor Lamb, who is running in a March 13 special election in a southwest Pennsylvania district that Mr. Trump won by 20 percentage points. Mr. Lamb is a 33-year-old Marine veteran who was a federal prosecutor in Pittsburgh before resigning in October to run.
Another former federal prosecutor—former Navy helicopter pilot and mother of four Mikie Sherrill—is running to replace New Jersey Republican Rodney Frelinghuysen, who chairs the House Appropriations Committee and announced last month that he wouldn’t seek re-election.
It is more common for U.S. attorneys—the top federal prosecutor in each district—to seek political office. Democrat Doug Jones, Alabama’s newest senator, for example, served as a U.S. attorney in Alabama in the Clinton administration. But it is rarer for line-level prosecutors, who are career staffers rather than political appointees.
Several of the candidates defended the Justice Department and the FBI in recent weeks as they have come under fire, including from the GOP memo on the surveillance of Mr. Page.
Rep. Will Hurd (R., Texas), who is running for re-election in a House district that stretches along the Texas-Mexico border, wrote a column saying he had voted to make the memo public because he was “not confident that proper vetting occurred” in seeking approval for the surveillance.
Jay Hulings, a former prosecutor and the front-runner in the Democratic primary in the race for that seat, described the memo as a “political stunt,” adding in a tweet, “The idea that releasing the memo has anything to do with civil liberties is laughable.”
Write to Aruna Viswanatha at Aruna.Viswanatha@wsj.com