Now that we know FBI agents deceived the court to get the warrants to spy on Trump campaign aide Carter Page, the big question is: Was this the exception, or the rule?

That is, has the bureau taken to regularly lying in its 1,500 requests a year for Foreign Intelligence Surveillance Act wiretaps — or did higher-ups opt to go rogue in this particular case?

The Foreign Intelligence Surveillance Court’s presiding judge, Rosemary Collyer, last week issued a rare public order telling the FBI to submit a sworn statement by Jan. 10 laying out what it has done and what else it plans to do to ensure this outrageous malfeasance won’t repeat.

Because FISA warrants are secret, no opposing counsel gets to contest the bureau’s claims — so agents are supposed to scrupulously level with the court about any weaknesses in their applications.

But in Page’s case (at least), they did the reverse — one lawyer even falsified info to conceal the fact that Page had a history of voluntarily reporting on Russians to the CIA. And, as Collyer noted, FBI lawyers and agents “falsely represented” that the infamous — and uncorroborated — Christopher Steele dossier “had been used in criminal proceedings.” All four applications relied on Steele’s “reporting” in claiming Paul Manafort used Page as an intermediary with Russia — but didn’t note that Page told people he’d never once spoken to Manafort.

Indeed, as Inspector General Michael Horowitz told the Senate last week, it’s a major mystery why the FBI even kept asking to renew the warrants, as “agents [were] talking to one another about why Page is even a subject anymore,” since they’d developed zero evidence that he was a foreign agent and plenty of info undercutting that claim, including evidence that Steele was profoundly unreliable.

The FISA law rightly allows for secret wiretaps to guard the nation’s security, with strict rules meant to prevent abuse. Yet here was massive abuse in a case of the utmost sensitivity, a presidential campaign allegedly colluding with a malign foreign power — and a case overseen by the very top ranks of the FBI and Justice Department.

Were they playing fast and loose because they were investigating a presidential candidate and then the sitting president? Or was rule breaking so routine that they didn’t even think about it?

To find out, Horowitz testified, he’s doing an emergency audit of other FISA applications for both counterintelligence and anti-terror warrants.

Disgraced former FBI chief Jim Comey insists his people had no anti-Trump bias, or at least didn’t act on it in this investigation. But the only alternative explanation — that the bureau on his watch took to routinely abusing its national-security powers — will make him look even worse.