Despite the controversy that has ensued over the manner in which Trump fired Comey and the overblown comparisons to President Richard Nixon’s firing of special prosecutor Archibald Cox during the Watergate scandal, the simple reality is that Comey’s firing was both legally proper and politically necessary. None of this is to justify the inept way in which it was handled by a politically incompetent Trump administration. Nevertheless, Comey had politicized the FBI during the 2016 presidential campaign and he lacked the political skills to restore public confidence in the non-partisan character of the agency he headed.

Comey is widely regarded as a man of personal integrity. He first became known to the public when he threatened to resign rather than reauthorize a post-9/11 surveillance program that he viewed as legally suspect, even though it had the support of President George W. Bush and White House Counsel Alberto Gonzales. Attorney General John Ashcroft had been hospitalized for gall bladder surgery, and while he recuperated, Comey was filling in as acting attorney general. Comey not only refused to renew the program when authorization for it was imminently expiring, but he headed off an attempt by Andrew Card, Bush’s chief of staff, and Gonzales to circumvent Comey by making a bedside appeal to the ailing Ashcroft.

Comey’s willingness to challenge presidential authority thus made him a seemingly ideal candidate for FBI director when he was appointed in 2013. The FBI has historically cultivated a reputation for non-partisan independence from both presidential and congressional interference.

Yet during the 2016 presidential election, Comey decided not to prosecute Democratic presidential candidate and former Secretary of State Hillary Clinton for her actions regarding the handling of classified material on a private email server. In a May 9 memo, Rod Rosenstein, Trump’s deputy attorney general, argued that the former FBI director had improperly usurped the authority of the Justice Department in making that decision. That led Rosenstein to the conclusion that Comey should be terminated.

The function of the FBI is to investigate alleged wrongdoing and develop evidence for prosecutors. It was the responsibility of the attorney general at that time, Obama appointee Loretta Lynch, and her prosecutors to determine whether the evidence was sufficient to proceed and impanel a grand jury. Rosenstein’s memo impressively cites the opinions of former attorneys general and other legal authorities to support his claim that Comey erred both in making the decision not to proceed and then using a press conference to criticize Clinton for being irresponsible while announcing he would not indict her.

Having usurped final decision-making authority over this case in the decision not to prosecute, Comey then felt compelled to publicly reopen the investigation just days before the election when new evidence surfaced, despite the long-standing tradition that FBI investigators reopen investigations without public fanfare. Not only did Comey err in his judgments, he subsequently refused to admit fault despite overwhelming and compelling criticism of his decisions. Rosenstein properly concluded, “The FBI is unlikely to regain public and congressional trust until it has a Director who understands the gravity of the mistakes and pledges never to repeat them. Having refused to admit his errors, the Director cannot be expected to implement the necessary corrective actions.”

We now know that Trump intended to fire Comey even before the Rosenstein memo was drafted. The president admitted in an interview with NBC’s Lester Holt that he fired the director because he was upset with the FBI investigation into allegations that the Trump campaign had conspired with the Russians to defeat Clinton. Regardless of the exact reason for Comey’s firing, Rosenstein has stood by his conclusions. “I wrote it. I believe it. I stand by it,” he told senators in a private briefing Thursday, according to Fox News, calling Comey’s handling of the Clinton email investigation “wrong and unfair.”

Comey is a decent man who did his best under trying circumstances, but his errors of judgment damaged the agency he directed. For all of Trump’s self-inflicted political damage in the way he has handled this situation, he may yet nominate a new director who will do a better job than Comey did of restoring public confidence in the impartiality of the FBI.

Donald Brand is a professor of political science at the College of the Holy Cross.