(CNN) Joe Biden in a 1993 speech warned of "predators on our streets" who were "beyond the pale" and said they must be cordoned off from the rest of society because the justice system did not know how to rehabilitate them.

Biden, then chair of the Senate Judiciary Committee, made the comments on the Senate floor a day before a vote was scheduled on the Senate's version of the Violent Crime Control and Law Enforcement Act.

His central role in shaping and shepherding the tough-on-crime bill will likely face scrutiny in a Democratic primary should he run for president in 2020. His 1993 comments, which were in line with the broad political consensus to tackling crime at the time, are at odds with a new bipartisan coalition of activists and lawmakers who are trying to undo what they say is a legacy of mass incarceration fostered by that era.

Biden's word choice could also pose a problem with a new generation of Democrats who view the rhetoric at the time as perpetuating harmful myths about the black community.

CNN's KFile came across the 1993 speech during a review of the former vice president's record.

President Bill Clinton in 1994 signed the crime bill into law with broad bipartisan support as violent crime rates peaked in the US in the early 1990s. Included in the law was the federal "three strikes" provision, mandating life sentences for criminals convicted of a violent felony after two or more prior convictions, including drug crimes.

"We have predators on our streets that society has in fact, in part because of its neglect, created," said Biden, then a fourth-term senator from Delaware so committed to the bill that he has referred to it over the years as "the Biden bill."

"They are beyond the pale many of those people, beyond the pale," Biden continued. "And it's a sad commentary on society. We have no choice but to take them out of society."

In the speech, Biden described a "cadre of young people, tens of thousands of them, born out of wedlock, without parents, without supervision, without any structure, without any conscience developing because they literally ... because they literally have not been socialized, they literally have not had an opportunity." He said, "we should focus on them now" because "if we don't, they will, or a portion of them, will become the predators 15 years from now."

Biden added that he didn't care "why someone is a malefactor in society" and that criminals needed to be "away from my mother, your husband, our families."

Bill Russo, a spokesman for Biden, said high violent crime rates at the time was key context to understanding the bill and that, "Senator-Biden's strong rhetoric" was in response to Republican critiques that past efforts had been too soft on crime.

"Then-Senator Biden was referring specifically to violent crimes in the selected quotes. He was not talking about a kid stealing a candy bar, but someone who committed sexual assault, manslaughter, or murder," Russo told CNN in an email. "In contrast, he says in the same speech that we need a different approach for nonviolent crimes. Specifically, he says we 'need to keep people who are first time offenders, non-violent offenders, or potential first-time offenders who in fact are people getting themselves into the crime stream from the first time -- that they should be diverted from the system.'"

Biden's spokesman added the 1994 crime bill included funding "to keep individuals who committed first-time offenses and non-violent crimes out of prison and instead in treatment and supervision," and that Biden advocated for prevention funding. Russo also pointed to two provisions of the bill that led to Biden's strong support of its passage: bans on high-capacity magazines and assault weapons and the Violence Against Women Act.

Biden defended the 1994 crime law as a whole in a 2016 interview with CNBC , saying, "By and large, what it really did, it restored American cities."

But more recently, at an event talking about criminal justice in January, Biden said , "I haven't always been right. I know we haven't always gotten things right, but I've always tried."

He highlighted his later work with President Barack Obama to address the sentencing disparity for crack versus powder cocaine, saying, "It was a big mistake when it was made," he said at the National Action Network's Martin Luther King Jr. breakfast in Washington. "We thought, we were told by the experts, that crack you never go back, it was somehow fundamentally different. It's not different. But it's trapped an entire generation."

In the decades since it passed, portions of the act have been singled out by critics as contributing to the expansion of mass incarceration, particularly of African Americans. Speaking about mass incarceration in 2015, Bill Clinton said he "signed a bill that made the problem worse, and I want to admit it."

In 1993, Biden spoke to the broad political consensus that had formed around tackling violent crime.

"The consensus is A), we must take back the streets," Biden said, "It doesn't matter whether or not the person that is accosting your son or daughter or my son or daughter, my wife, your husband, my mother, your parents, it doesn't matter whether or not they were deprived as a youth. It doesn't matter whether or not they had no background that enabled them to become socialized into the fabric of society. It doesn't matter whether or not they're the victims of society. The end result is they're about to knock my mother on the head with a lead pipe, shoot my sister, beat up my wife, take on my sons."

Biden added in his speech that rehabilitation could not be a condition for release or sentencing, because the United States criminal justice system didn't know how to rehabilitate offenders.

"I'm the guy that said rehabilitation, when it occurs, we don't understand it and notice it and even when we notice it and we know it occurs, we don't know why," he said. "So you cannot make rehabilitation a condition for release."

The consensus, Biden again said, was the need to make streets safer. With an impassioned plea, Biden said he did not care what led someone to commit crimes.

"I don't care why someone is a malefactor in society. I don't care why someone is antisocial. I don't care why they've become a sociopath," Biden said. "We have an obligation to cordon them off from the rest of society, try to help them, try to change the behavior. That's what we do in this bill. We have drug treatment and we have other treatments to try to deal with it, but they are in jail."