There was one exchange last night that really captured my attention. I wasn’t able to watch the entire Democrat debate on CNN Wednesday (a blessing, I know) but one back and forth between Senator Cory Booker and former Vice-President Joe Biden was something to see. Criminal justice reform was the topic and while pointing out Biden’s boast that every major crime bill since the 1970s has had his name on it, Booker punched up by questioning Biden’s track record.

After Booker took a shot at Biden’s very long record in Congress where he didn’t solve all the troubles in the world, Biden pointed to Booker’s own record with Newark’s police force during his time as that city’s mayor. He clapped back at Booker for hiring “Rudy Guiliani’s guy” in 2007 to deal with Newark’s police department troubles. When he began a laundry list of grievances against Booker’s time in office and the police department’s policies, he referred to Booker as “the president” then corrected it to “the future president”, which was just an odd slip of the tongue given they are both vying for the job. No one really thinks Cory Booker will ever be president.

“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.”

Biden was promoting his new plan and Booker was making the point that after more than 40 years of not getting it done, it takes some nerve from Biden to question another candidate’s ability to make the changes that Democrats want in criminal justice reform.

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.

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.”

Sure, Booker can claim he’s worked on criminal justice reform in the Senate but it is a fact that true reform has been ushered in by President Trump in the form of the First Step Act. That was not the brainchild of Senator Booker or of the Obama administration. Funny, neither man acknowledged President Trump’s success.

Booker was feigning amazement that Biden is running on his record. What else does a career politician have to run on, though? Biden had clearly been prepped for this debate and was determined to show he can take a punch and return one. At this point in the primary race, it is crucial that Biden showed he has staying power and isn’t too old and tired for the job. Booker chastised Biden for continually bringing up former President Obama, but, again, that is his calling card to be in the race. Without Barack Obama, Joe Biden would be just another senator who doesn’t know when it is time to retire. We all know he’d still be in the Senate and still historically wrong on all the big issues.

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.”

The Kool-Aid reference was the best. Not because of Booker’s lame comeback to Biden, but because of the company’s Twitter game. Cory Booker said to Joe Biden that Joe didn’t know what he was talking about. He did that by bringing in an alleged saying from the hood (it might be fake, like his friend T-Bone). “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.” Kool-Aid took that gift and produced Twitter gold.

Look, Cory Booker scored some points for bravado against Biden. Both men had something to prove and both probably did it. Biden is at the top of the polls and it is for Booker to move the needle in his poll rankings. He’s at 1.6% nationally, according to Real Clear Politics. Biden is at 32%. Booker will need more Spartacus moments to prove he’s worthy of remaining in the primary going forward.