Since taking office, Comey has repeatedly injected his views into executive branch deliberations on issues such as sentencing reform and the roots of violence against police officers. He has undermined key presidential priorities such as crafting a coherent federal policy on cybersecurity and encryption. Most recently, he shattered longstanding precedent by publicly offering his own conclusions about the FBI’s investigation into Hillary Clinton’s email. (The FBI did not respond to a request for comment.)

It would be difficult to argue—in terms of temperament, manner, or motivation—that he is, or ever will be, the next J. Edgar Hoover. But increasing numbers of critics believe he has displayed a worrying disregard for the rules and norms that have constrained all but one of his predecessors, straying with blithe confidence—and with increasing regularity—across the fine line that separates independence from unaccountability.

These concerns were only whispered about until July, when the FBI director’s public disposition of the Hillary Clinton email investigation stoked national controversy. Since then, even some of Comey’s supporters have been forced to concede that his exercise of power has been without precedent in the post-Hoover era. Among dozens of current and former Justice Department officials, this realization has given way to a rising sense of alarm: that our next president will find Comey just as untouchable as Hoover once was—and perhaps nearly as troublesome.