Consider the episode for which he is perhaps most famous: opposing the George W. Bush administration’s “warrantless wiretapping” program in 2004. The left cast the then-deputy U.S. attorney general as a hero, breathlessly relating how he had rushed to the hospital bedside of then-Attorney General John Ashcroft to oppose reauthorization of the program. Mr. Obama, in choosing Mr. Comey, furthered this lore, feting him as a man who “was prepared to give up a job he loved rather than be part of something he felt was fundamentally wrong.”

Yet there was nothing tough or bold about opposing a program that was always going to be explosively controversial. Intervening wasn’t brave; it’s what any watch-your-own-backside official would do. There was nothing courageous in later spinning his role, or tarnishing well-meaning government lawyers whose interpretations of the policy differed from his own. Tough would have been standing behind a program that was vital in the war on terror; tough would have been defending the policy when it became a lightning rod for liberal and media criticism.

There was nothing tough, when Mr. Comey was a federal prosecutor in 2003, about expending vast time and resources to harass banker Frank Quattrone over the wording of a single ambiguous email. Tough would have been withstanding the post-Enron, antibusiness populist climate and refusing to burnish one’s prosecutorial credentials by turning Mr. Quattrone into a whipping boy. There was nothing tough about continuing to defend the FBI’s hapless investigation of non-anthrax-mailer Steven Jay Hatfill. Tough would have been admitting the FBI had bungled it.