Editor's Note: This article is one of 50 in a series about Trump's first two years as president.

On March 16, 2018, just days before he was eligible to receive a federal pension for his 21 years at the bureau, former Deputy FBI Director Andrew McCabe was fired by then–Attorney General Jeff Sessions. The president took to Twitter to celebrate.

“Andrew McCabe FIRED, a great day for the hard working men and women of the FBI—A great day for Democracy,” he wrote. “Sanctimonious James Comey was his boss and made McCabe look like a choirboy. He knew all about the lies and corruption going on at the highest levels of the FBI!”

The tweet was, in many ways, typical of Donald Trump’s presidency: crude, vindictive, and possibly incriminating—McCabe and former FBI Director James Comey were, after all, potential witnesses against Trump in Special Counsel Robert Mueller’s obstruction-of-justice investigation. And McCabe was the one who reportedly called for such a probe to begin with—and went as far as to open one—after Trump fired Comey in May 2017. “I am being singled out and treated this way because of the role I played, the actions I took, and the events I witnessed in the aftermath of the firing of James Comey,” McCabe said in a statement. “This attack on my credibility is one part of a larger effort not just to slander me personally, but to taint the FBI, law enforcement, and intelligence professionals more generally.”

Even as Trump has been waging a very public war on the DOJ—in one tweet, he called it the “‘Justice’ Department,” implying that it wasn’t worthy of the name—he has also been working to bring it further under his wing. With multiple federal investigations under way that could implicate him, his family, and his namesake organization in criminal activity, Trump fired Sessions in November and replaced him with Sessions’s chief of staff, Matthew Whitaker, an ultra-loyalist whom the White House had considered its eyes and ears in the Justice Department. The appointment was problematic not only because of Whitaker’s past attacks on the special counsel’s probe, which he now oversees, but also because it may have been unconstitutional.

Appointing Whitaker is arguably the furthest Trump has gone (so far) in trying to exert direct control over an investigation that is closing in on his inner circle. Perhaps the least surprising—and yet still, somehow, the most shocking—revelation to date about Trump’s warped perception of the Justice Department, however, came that same month, when The New York Times reported that Trump had wanted the Justice Department to prosecute two of his nemeses, Comey and Hillary Clinton. “I don’t know of anyone who has ever thought that it would be remotely tolerable in any way for a president to instruct [the] DOJ to prosecute his political opponents,” David Kris, the assistant attorney general for the DOJ’s national-security division from 2009 to 2011, told me when Trump’s comments were reported. “That is just plain ... out of bounds, un-American, wrong.”

Trump is not unique in his yearning to prosecute political enemies while trying to control those investigating him. Richard Nixon famously had an “enemies list,” and several presidents have had a tense relationship with the FBI. President Clinton and Director Louis Freeh, for example, who was very supportive of the Monica Lewinsky investigation, were notorious rivals. But there is no evidence that Clinton tried to have Freeh fired, and their disagreements largely remained out of sight.  

By contrast, historians say, Trump’s open combat against the FBI—on Twitter, at political rallies, and in interviews—is unprecedented. Trump is also just the second president to fire an FBI director. (Clinton fired William Sessions, a federal judge appointed by Ronald Reagan, for alleged ethical violations.) And Trump is the first to do so while under investigation by that same director. The closest parallel is Nixon’s attempt to manipulate the Watergate investigation that targeted him and his associates. But that scheme was quickly exposed and, ultimately, used against him.  

Nixon’s fate is precisely why, post-Watergate, presidents have been encouraged to maintain a healthy separation from the Justice Department—not just to protect the independence of prosecutorial decisions, but to protect themselves as well. Trump, of course, is not one for tradition. “I said on the Department of Justice, I would stay uninvolved,” he told Fox News last June. “Now I may get involved at some point if it gets worse.”

John Dean, who served as Nixon’s White House counsel from 1970 to 1973, emphasizes that after Watergate, it became generally accepted that the White House would stay out of DOJ business. But “Trump ignores all norms,” Dean told me—which is why, following the Trump presidency, those norms “will probably become law.”

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