James Comey surely had no idea what he was in for.

The FBI director knew that his decision to notify Congress of the reopening of the Clinton email investigation would cause a firestorm. But even he must be taken aback by the tsunami of obloquy that reaches all the way up to the president of the United States.

The day before yesterday, James Comey was the ultimate argument from authority, cited by every Democrat for the proposition that Hillary Clinton’s private email setup was no big deal. Now, he is accused of violating the law, of being tantamount to a sex offender, and of returning the specter of J. Edgar Hoover to Washington, D.C.

Perhaps Comey’s letter was ill-advised; it certainly wasn’t ill-intentioned. Any reasonable critic of Comey should concede that — coming unexpectedly into possession of 650,000 more emails possibly relevant to an investigation that he had told Congress was closed — he was in a tricky spot.

But most of Comey’s detractors aren’t interested in his dilemma or in the Department of Justice protocols they claim to hold so dear. No, Comey’s sin was putting at risk Clinton’s electoral prospects, and he is consequently the object of a campaign of personal destruction whose motive is nakedly political.

President Barack Obama’s spokesman said the other day that he wouldn’t criticize or defend Comey. That Olympian detachment quickly became inoperative. “I do think that there is a norm that when there are investigations,” Obama said in an interview, “we don’t operate on incomplete information, and we don’t operate on leaks.”

There’s also a norm against a president publicly slamming his FBI director. But now it’s open season on Comey.

The New York Times ran a front-page story headlined “James Comey Role Recalls Hoover’s F.B.I., Fairly or Not.” The “fairly or not” construction is a warrant to publish anything. Why not “Obama Accused of Being Born in Kenya, Fairly or Not.” Or “The Clintons Accused of Murdering Political Opponents, Fairly or Not.”

The main supporting quotation in the piece is from Georgetown University’s Sanford Ungar. Even he stipulates, “I don’t mean to smear Comey, and it may be an unfair comparison.” Then why make it? According to Ungar, the connection between Hoover and Comey is that the notorious 20th-century FBI director “would weigh in on issues without warning or expectation.”

Really? Hoover’s problem was that he occasionally popped off? Not the domestic spying, the political blackmail and the attempts to destroy Martin Luther King Jr.?

Harry Reid accused Comey of violating the law — specifically the Hatch Act — which is stupidly malicious even for Reid, who doesn’t have an ounce of Comey’s integrity even on one of the FBI director’s worst days.

The teenager who says she sexted with Anthony Weiner told BuzzFeed that she felt re-victimized by Comey. Weiner’s alleged victimization of her consisted of sending her lewd messages and trying to exploit her; James Comey’s victimization consisted of finding emails related to another investigation on Weiner’s computer. How can he sleep at night?

Ian Millhiser of Think Progress argues that Comey should be fired because his notification to Congress is the first step on a slippery slope toward the FBI violating the civil liberties of all Americans. First, they came for Hillary Clinton …

The Democrats portray themselves as the institutionalists in this election, protecting all that is good and decent from the onslaught of Donald Trump. But the Comey episode shows that their commitment to our institutions is coterminous with their political interest. As soon as Comey crossed them, they turned on him viciously and didn’t care if the FBI was collateral damage.

The lock-step attack, from the cable TV talking heads to the president, is something to behold. It’s not just that the Clintons will bend every rule and try to destroy anyone who gets in their way; they will enlist everyone on their side to do the same.

This is how a Clinton administration will work. Consider yourself warned — again.

Rich Lowry is a syndicated columnist. He can be reached via e-mail at: comments.lowry@nationalreview.com.