The 5 minutes when Biden and Booker's simmering fight erupted

Cory Booker wasn’t going to let Joe Biden expunge his 40-year tough-on-crime record.

Seemingly every candidate on the Democratic debate stage Wednesday night wanted to provoke a disagreement with Biden and prove their mettle against the primary polling leader. But confrontation with Booker was weeks in the making, after the two sparred online and in the press over Biden’s comments about segregationist senators and the former vice president’s long legislative record.

And Booker, in search of his first bona fide “moment” as he tries to work his way up in the presidential race, came ready to lunge into his critique of Biden’s new criminal justice proposal as too little, too late to fix the problem of mass incarceration, after Biden’s authorship of punitive crime legislation in the ‘90s.

“This is a crisis in our country because we have treated issues of race and poverty, mental health and addiction with locking people up and not lifting them up,” Booker said, turning to Biden. “And Mr. Vice President has said that since the 1970s, every major crime bill — every crime bill, major and minor — has had his name on it.”

The five-minute exchange between Booker and Biden lacked the sheer force of Kamala Harris’ surprise confrontation over race and busing last month — because Booker’s campaign targeted Biden on the issue just last week, making the debate-night confrontation inevitable. But Booker forced the front-runner to reckon in real time with his role in producing an unequal justice system in America, while Biden showed off a new edge in his debating skills that was missing against Harris in June.

Biden spoke first, focusing on all the changes he wants to see in the criminal justice system, including prioritizing rehabilitation over prison and giving prisoners more housing and education opportunities.

In the meantime, Booker folded his hands together and bowed his head in preparation. When it was his turn, he was calm and stern, at turns largely avoided the overly-scripted “Spartacus” persona that undermined high-profile Senate moments.

Biden has evolved on criminal justice alongside other major leaders in his party. But in a field of younger candidates, and in the age of Black Lives Matter, he has still been reluctant to apologize — or even explain the context — for pushing laws that many activists and reformers believe led to a huge national spike in the prison population.

After noting Biden’s involvement in past crime bills the Democratic Party now disavows, Booker calmly pressed on: “This is one of those instances where the house was set on fire and you claimed responsibility for those laws. And you can't just now come out with a plan to put out that fire. We have got to have far more bold action on criminal justice reform.”

Biden chose to return fire rather than engage directly in the substance — a sign of more thorough preparation to deflect attacks than in the last debate, when Harris successfully ambushed him.

Biden quickly noted that the tough-on-crime bills he backed were passed “years ago, and they were passed overwhelmingly.” But, after a slip-up in which he called Booker the “future president,” Biden flashed forward to 2007, when then-Sen. Biden had said he advocated for eliminating the criminal disparity between crack and powder cocaine.

“In 2007, you became mayor and you had a police department,” Biden said to Booker. “You went out and hired Rudy Giuliani’s guy and you engaged in stop and frisk. You had 75 percent of those stops reviewed as illegal.”

“The Justice Department came after you, saying you were engaging in behavior that was inappropriate,” Biden added in a flurry of bullet points. “And then, in fact, nothing happened the entire time you were mayor.”

For Biden, raising Booker’s own police problems as mayor of Newark helped him spin out of a quagmire. Yet it was also a key moment for him to demonstrate that he has the fight to take on a pugilistic President Donald Trump — who, incidentally, has forged a criminal justice record in his first term. While Booker has worked on the issue for years in the Senate, it was Trump who actually signed the First Step Act that reformed sentencing and prison reentry.

As Biden spoke, Booker scribbled down some notes. He smiled.

And he joked about Biden endorsing his presidency “already.”

But then he turned serious. “We have a system right now that's broken,” Booker shot back, saying that he inherited troubled cops in a department facing decades of challenges. He contended that the head of the New Jersey ACLU said he put in place national standard-setting accountability.

Biden, rocking forward on his toes, tried to jump back in — another indication that he was ready this time. But Booker wouldn’t allow him out of his grip.

“And if you want to compare records — and I’m shocked that you do — I am happy to do that,” Booker said. “Because all the problems that he is talking about that he created, I actually led the bill that got passed into law that reverses the damages that your bills that you were ... bragging, calling it the Biden crime bill up until 2015.”

Booker got the fight he wanted. And it was the best he’d looked all year.

When Biden came back with his line about “hiring Rudy Giuliani’s guy,” Booker had a one-liner ready.

“Mr. Vice President, there's a saying in my community,” Booker said, “that you’re dipping into the Kool-Aid and you don't even know the flavor.”