Now, Rosenstein is becoming another experienced employee to exit the Department of Justice under the Trump administration. He filed his resignation, effective this Saturday, late last month.

Dozens of such employees have left the department since President Donald Trump’s inauguration in January 2017. At least 12 have resigned by personal choice, citing career changes or unabated concerns with the administration. Another 44 have resigned under pressure from the administration, including former Attorney General Jeff Sessions and the 43 Obama-era district attorneys he forced out in March 2017.

Still four more employees have been fired, including former FBI Director James Comey, whose ousting sparked the Mueller investigation; former FBI Deputy Director Andrew McCabe, who was fired just two days before his retirement; former Southern District of New York DA Preet Bharara, who refused to step down in the purge of 2017; and Sally Yates, who served as acting attorney general for just 11 days in January 2017 before angering Trump by refusing to enforce his travel ban.

Such turnover is not unheard of: administrations usually bring in their own staff of district attorneys, and, as Rosenstein notes in his resignation letter, few in his position serve longer than two years. A Brookings Institution study on executive staff changes found that former President Barack Obama saw a 43% turnover of his most influential staff in the third year of his presidency, likely evidence that this two-year trend reaches across departments.

Trump, however, had more departures in his first year than any of his five predecessors.

The Brookings study found that the Trump administration saw a 34% turnover of its most influential employees within the first year, compared to 9% in Barack Obama’s first year and 6% in George W. Bush’s first year. According to the study’s author, the initial slew of short-term staff might be due to “the president’s focus on loyalty over qualifications,” leading to inexperienced employees unable to maintain the position, and the “borderline chaos that characterized the overall tenor of the administration’s first year.”

These numbers apply to the full executive staff, not just the DOJ, but might represent an overarching trend of Trump’s presidency. While some staff—like Rosenstein—have departed the administration amicably, others have resigned with less enthusiasm.

Diana Flynn had been working in the civil rights division of the DOJ since the 1980s, but the climate under the Trump administration forced her to pursue employment elsewhere. According to Flynn, policymakers ceased to seek the guidance of career staff with expert knowledge on the issues—a stark change from past administrations—because it seemed the president wanted his policies implemented immediately, with little regard for the oversight or procedure that ensure any new regulation properly benefits the country.

“At least in some divisions—for example the Civil Rights Division, which is where I worked for close to 34 years—the career people seemed to be avoided quite deliberately and given very little opportunity to do their jobs and to be sure that decisions were made properly, based on the evidence,” Flynn told Fortune.

In prior administration transitions, said Flynn, even those with differing political directions would respect the knowledgeable history of the existing staff.

“Quite frequently there would be extensive consultation and review to be sure that all of the interests were recognized. It was taken very seriously certainly by the career staff, but also by most of the administrations that came in, that the U.S. Department of Justice represents all the people and the interests of all the people,” said Flynn.

Under Trump, “that all went away.”

“The career staff with highly in-depth and specific knowledge about things seemed to be bypassed to the maximum extent possible in decision making,” said Flynn. “The result was positions came out with which many people vehemently disagreed, would have a great deal of problems morally enforcing.”

The DOJ, however, says it continues to seek the guidance of longtime staff.

“There’s constantly a dialogue with career attorneys in all the different divisions,” a DOJ official told Fortune. “The advice and the input that we get from career staff is regarded as very important, especially because they have that institutional knowledge.”

Flynn argues that very knowledge is being lost.

“There is long term damage being done by this,” she said of employee resignations.

Former DOJ Assistant Branch Director Joel McElvain left the department in July 2018 after more than 20 years. Although he didn’t specify political differences as his reason for leaving, McElvain filed his resignation letter just one day after then-Attorney General Sessions said the DOJ would not defend the Affordable Care Act.

Hui Chen, a former DOJ consultant and corporate ethics expert, made her reason for leaving the department in June 2017 very clear: “trying to hold companies to standards that our current administration is not living up to was creating a cognitive dissonance that I could not overcome,” she wrote in a LinkedIn post.

These two are just a couple of those who left, but the DOJ has 115,000 employees. Rosenstein advised these employees to “faithfully pursue the Department’s law enforcement mission and the Administration’s goals in a manner consistent with laws, regulations, policies, and principles.”

“Be prepared to face criticism. That is part of the job,” he said in a 2018 address to the House Judiciary Committee. “But ignore the tyranny of the news cycle. Stick to the rule of law, and make honest decisions that will withstand fair and objective review.”

Flynn, however, did not feel the DOJ was making such honest decisions. She said her departure was prompted not just by the lack of consultation, but by the administration’s implementation of “extreme and cruel policies” targeting the LGBTQ+ community in a way that showed “cruelty was the point.”

Shortly after Sessions’ appointment, the administration withdrew its guidance protecting trans and gender-nonconforming students. Later, Title VII anti-discrimination protections for gay, lesbian, and trans individuals were withdrawn. Flynn left the department in March 2018, just as the DOJ was beginning to require trans people be confined in prison facilities based on their birth sex as opposed to their identity.

“They got where they wanted to go, they did it quickly, and in my opinion they had very poor legal justifications given for it,” said Flynn of the Trump administration’s changes.

The department still has 115,000 employees “that work diligently every day to support the administration’s decisions,” said the DOJ official, even through policy changes. Many of these may be career staff, but some who left worry about the future ahead.

“When you lose the institutional memory and you lose the people that were willing to speak truth to power and you lose the people that were actually experienced in determining properly what the law is and enforcing the law, it’s going to be very difficult to rebuild that capacity even when this difficult interlude with the Trump administration is over,” said Flynn. “It’s a task I think no prior administration has had to face.”