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

The FBI director knew his decision to notify Congress of effectively reopening 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’s accused of violating the law, threatening democracy and returning the specter of J. Edgar Hoover to Washington, DC.

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 Obama’s spokesman said the other day that he would neither criticize nor 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 broadcast Tuesday, “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, especially when it’s in order to get in lockstep with a partywide pile-on.

The most telling critique of Comey is that he never should have started talking about the Clinton email case back in July. This was probably a mistake, but it was an excess of transparency.

He figured, reasonably enough, that political sensitivities were so high and suspicions had been so aroused by Attorney General Loretta Lynch’s runway meeting with former President Bill Clinton (remember: all these people care about is protocol!) that he should be unusually open.

If Democrats didn’t like his public critique of Clinton, they were happy to cite his opinion that “no reasonable prosecutor” would bring the email case and elevate him to a modern-day Eliot Ness.

But that was one week ago. Now, it’s literally permissible to say anything about 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 whatsoever. 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 academic Sanford Ungar. Even he stipulates, “I don’t mean to smear Comey, and it may be an unfair comparison.” Then why make it? The connection that he discerns between Hoover and Comey is that the notorious 20th-century FBI director “would weigh in on issues without warning or expectation.”

Really? The problem with Hoover was that he occasionally popped off? Not the domestic spying, the political blackmail and the attempts to destroy Martin Luther King Jr.? If only Hoover had had better message discipline, he would’ve been remembered as a hell of a director.

Then there’s Harry Reid, who 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 very worst days.

Ian Millhiser of Think Progress argues 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 are portraying themselves as the institutionalists, protecting all that is good and decent in our government from the onslaught of Donald Trump. But the Comey episode shows how their commitment to our institutions is co-terminous with their political interest.

The lockstep 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.