News that the F.B.I. used a secret informant to investigate Russian infiltration of the Trump campaign has touched a raw nerve in the White House, where President Donald Trump was already wary of a Deep State plot against him. As my colleague Gabriel Sherman reports, Trump has latched onto the conspiracy that the Obama administration may have entrapped his advisers and planted evidence linking them to Russia—and may even have additional agents working inside the administration. “There’s a paranoia about who else is one,” one Trump official said. Gripped by Nixonian fears, Trump on Sunday demanded that the Justice Department investigate itself to uncover whether the F.B.I. “infiltrated or surveilled the Trump campaign for political purposes—and if any such demands or requests were made by people within the Obama administration!”

The president’s order, issued over Twitter and made manifest the following day during a tense meeting with top D.O.J. officials, may have temporarily allayed Trump’s fury over Robert Mueller’s Russia probe. But according to veteran members of the D.C. bar, it may also have compounded his nettlesome legal problems. “I think that the president is acting like somebody who has something to hide,” Sol Wisenberg, a deputy special prosecutor during the Starr investigation, told me. “It seems to me the attacks, particularly by the president himself, have just grown exponentially in vitriol. They’ve kind of become maniacal, in a way. I think he’s worried about something. Typically, when you engage in conduct like that, you’ve got something to hide.”

Deputy Attorney General Rod Rosenstein ably defused the tensions with the White House by promising to fold the president’s inquiry into another, already ongoing internal probe. Still, the clash between president and Justice Department was a remarkable breach of historical precedent. “There is a reason why there has been a strict independence of the Justice Department when it comes to sensitive investigations,” Neal Katyal, who drafted the Justice Department’s 1999 special-counsel regulations, told me. “It is to avoid precisely the appearance, if not the reality, of government cover-ups.” Trump’s actions, he added, “are Exhibit A for why we needed a special counsel in the first place. That someone who behaves with this callous disregard for the rule of law when it comes to an investigation is exactly the reason why you need an independent investigation of him.”

For months, Trump’s attorneys managed to prevent the president from interfering in the Russia investigation, arguing that a conciliatory approach would provide the fastest route to his exoneration. As Mueller’s probe approached the one-year mark, however, the president grew restless, shaking up his legal team by replacing John Dowd with loose-cannon attorney Rudy Giuliani. Trump has since adopted a more aggressive, free-wheeling media strategy, with Giuliani playing offense, rather than defense, in the press. “I think he’s always maintaining his flexibility to at some point actually take action, to impede the investigation or shut it down altogether,” said Bob Bauer, who served as White House general counsel under Barack Obama. Trump’s lawyers, he noted, seem “very fond” of the constitutional theory that the president can’t obstruct justice, and that “he can do what he wants to the Department of Justice.”

It’s a brazen legal strategy, with Trump and Giuliani betting big on their ability to get any potential charges tossed out on procedural or constitutional grounds. Giuliani has argued, for instance, that Trump is not legally required to accede to a subpoena to testify before Mueller, and that he would be well within his rights to order Rosenstein to shutter the investigation. “I believe a president is open—and so this president is open—to a charge of obstruction. I don’t believe he has constitutional immunity,” said Bauer. “It’s particularly unhelpful to someone who’s under investigation for that kind of activity, to be, yet again, finding a way to disrupt the normal processes of the law enforcement community.”