The current administration’s implementation of Donald Trump’s orders is creating anxiety among law enforcement leaders throughout the country. Last year, ProPublica received a letter from some of our readers asking us to interview two agents who were just sworn in in recent months and recently defected to the ACLU. We started planning to do that, but recently learned more about the Los Angeles office’s experiences dealing with and managing internal dissent.

It started with a lawsuit against the Border Patrol, brought by a group of agents who didn’t want to do their jobs anymore. In 2015, that lawsuit reached the American Civil Liberties Union, which sued to stop officers from taking children off Border Patrol buses and transporting them to jails without the parents’ consent. The ACLU won that case and the agents took part in mediation. They became emissaries, and now they describe their struggle to persuade their supervisors that Border Patrol was finally practicing what it preached.

Three years later, Border Patrol’s internal troubles aren’t over. This month, the ACLU revealed that dozens of agents in the San Diego–Tijuana sector had signed an affidavit alleging that the Border Patrol retaliated against them, interfering with their lives and relationships, regardless of their use of force.

On one day in July, 91 agents working out of a San Diego patrol office filed the affidavit. The agents alleged that agents in the office under the command of David Aguilar, who still heads the Border Patrol in San Diego, had mishandled national intelligence, thrown out LGBT employees, subjected agents to harassment and retaliation, and intimidated employees from following up on intelligence reports. The agents also accused Aguilar of retaliating against the agent who filed the lawsuit in 2015.

The San Diego office says the whistleblowers are fabricating their story. Aguilar’s office told us that it conducted an internal investigation into all of the allegations in the affidavit, and found no evidence of the agents’ claims. Under Aguilar’s leadership, the agency has continued to implement changes to the hiring and training of agents.

What can we learn from what has happened in San Diego and the rancor that surrounds Border Patrol’s internal working environment? It’s a reminder that even when law enforcement officials are effective, especially when law enforcement officials are effective, they must strive to stay in sync with each other. It’s also a reminder that it is natural to make mistakes, that a staff—or a U.S. border patrol office—inundated with political and public pressure can be susceptible to some chaos.

The risk of an internal culture of corruption cannot be understated. Border Patrol officers have “confidences of their own,” says Chris Crane, the former chairman of the union that represents the agents. “They believe the agents want to maintain the integrity of what they’re doing and they want to maintain their own career. They’re not going to bring in any evidence that might result in the firing of the agent or some officer, and the clock starts ticking.”

But if the agency is to have any chance of expanding, it must insulate its ranks from outside pressures. Former New York City Mayor Rudy Giuliani, talking about presidential candidate Hillary Clinton, said this week: “Hillary is a criminal because she has more people having illegal wire-taps in her office than anybody else.” That’s a good summation of the dangers the president’s order presents to the nearly 14,000 people who regularly work for the Border Patrol, and what the agency faces in the current policy climate: We can’t be all that we say we are. That doesn’t mean, as the president suggests, that all of the current applicants will fail drug tests and others won’t be screened for violent behavior. But it means that the agency’s leaders, and its agents who ultimately run operations, must be accountable to themselves and one another, and they must be clear that following orders, while they are always duty-bound to do so, does not mean that they can, or should, push an agenda that they don’t think is right.

Ken Schwencke is a senior reporter at ProPublica