In a blistering battle with CNN host Jake Tapper on Sunday, Broward County’s sheriff refused to step aside in the wake of his department’s bungled handling of the Florida school massacre — even insisting at one point that he has provided “amazing leadership.”

Asked whether the killings at Marjory Stoneman Douglas HS might have been averted if his office followed up on a slew of prior calls about the shooter being mentally unhinged, Sheriff Scott Israel responded with an absurd answer.

“If ifs and buts were candy and nuts, OJ Simpson would still be in the record books,” he said.

Tapper, the anchor of “State of the Union, shot back that he had no idea what that meant and said with 17 dead, did the sheriff think he could have done something differently in light of the all red flags raised about accused shooter Nikolas Cruz.

“We understand everything wasn’t done perfectly,” Israel responded — then added, that’s life.

“If it happened in Los Angeles or Chicago or any other city, every person wouldn’t have performed perfectly,” he said. “That’s not what happens.”

An incredulous Tapper asked, “Are you really not taking any responsibility for the multiple red flags that were brought to the attention of the Broward sheriff’s office about this shooter before this incident, whether it was people near him, close to him calling the police?”

Israel replied, “Jake, I can only take responsibility for what I knew about. I exercised my due diligence. I’ve given amazing leadership to this agency.”

Tapper shot back, “Amazing leadership?”

Israel then tried to deflect questions about reports that four of his deputies cowered outside the school during the rampage instead of running inside to help the trapped teachers and students. One of them, Scot Peterson, retired after Israel suspended him without pay when his alleged cowardice came to light.

“You don’t measure a person’s leadership by a deputy not going into [the school]. … These deputies received the training they needed,” Israel said.

“Do I believe if Scot Peterson went into that building and there was a chance he could have neutralized the killer and saved lives, yes. But as far as anything else done at this point. I can’t say that.”

Tapper said Israel’s office listed 23 incidents involving Cruz and asked why nothing was done to keep a gun out of his hands, secure the school or keep an eye on him.

“On 16 of those cases, our deputies did everything right. Our deputies have done amazing things. … In five years, we’ve taken the Broward Sheriff’s Department to new levels,” he said.

“One person at this point didn’t do what he should have done,” Israel added. “It’s horrific. The victims here, the families, I pray for them every night. It makes me sick in the stomach that we had a deputy who didn’t go in.”

Israel said an investigation will determine if his deputies remained outside the school.

“Our investigation to this point shows that during this horrific attack, while this killer was inside the school, there was only one law-enforcement person, period,” Israel said. “And that was former Deputy Scot Peterson. Coral Springs arrived — a group of Coral Springs officers went in within, I think, about 4 minutes, we’re projecting, after the killer left the campus.”