Joe Biden was one tough public pool life guard, and he wasn’t going to let some black dude cause trouble on his watch.

The Democratic presidential front runner was in his old stomping grounds in 2017 and recounted a story where he threatened a group of black “bad guys” he didn’t want there.

“This was the diving board area,” he said, pointing with his Aviator sunglasses at the Wilmington, Delaware pool, “and I was one of the guards, and (indecipherable) there was a 3-meter board.

“If you fell off sideways, you landed on the damn—” he continued, but quickly correcting himself due to all the children nearby, “uh, the darn cement over there,” indicating the seriousness with which he took his life guard duties.

“And Corn Pop was a bad dude, and he ran a bunch of bad boys, and back in those days, to show how things have changed, one of the things you had to use was, if you used pomade in your hair, you had to wear a bathing cap,” Biden recounted.

Corn Pop apparently wasn’t wearing a bathing cap.

“So he was up on the board, wouldn’t listen to me, I said, ‘Hey, Esther, you, off the board, or I’ll come up and drag you off,'” Biden continued, referring to actress Esther Williams, who filmed a legendary pool scene in 1947’s “This Time For Keeps.”

“Well, he came off and he said, ‘I’ll meet you outside.’ Now my car— these were all public housing behind you,” Biden said, pointing behind the audience, “my car— there was a gate out here. I parked my car outside the gate. He said, ‘I’ll be waiting for you.’ He was with there with three guys with straight razors, not a joke,” Biden said, trying to emphasize the seriousness of this riveting tale of bravery and community heroism.

“There was a guy named Bill Wright, the only white guy and he did all the pools, he was the mechanic. I said, ‘What am I going to do?’ He said, ‘Come down here in the basement where mechanics— where all the pool filter is,” Biden said.

“You know the chain? There used to be a chain across the deep end. And he cut off a 6-foot length of chain, he pulled it up, he said, ‘You walk out with that chain. And you walk to the car and you say, you may cut me man, but I’m going to wrap this chain around your head.’ I said, ‘You’re kidding me.’ He said, ‘No, if you don’t, don’t come back,’ and he was right,” the presidential candidate continued.

“So I walked out with the chain,” he said, as the children behind him were growing restless, “and I walked up to my car, remember in those days, the straight razor, bang them on the curb, get them rusty, put them in the rain barrel, get them rusty, and I looked at him, but I was smart then, I said, ‘First of all, when I tell you to get off the board, you get off the board and I’ll kick out out again, but I shouldn’t have called you Esther Williams, I apologize,” Biden said.

He contended with the mea culpa, the tough guy Corn Pop relented.

“But I didn’t know that apology was going to work. He said, ‘You apologize to me?’ I said, ‘I apologize but not for throwing you out, but I apologize for what I said.’

“He said, ‘Okay, close the straight razors,’ my heart began to beat again,” Biden said.

He didn’t say what ever became of Corn Pop. Maybe he’s friends with T-Bone.