Joe Biden admits past mistakes on criminal justice

But his role in helping to pass tough-on-crime legislations in the 1990s — that experts say have led to an era of mass incarceration that disproportionately affected black Americans — will certainly face scrutiny.

"I haven't always been right. I know we haven't always gotten things right, but I've always tried. … It was a big mistake when it was made. We thought, we were told by the experts, that crack you never go back, [and that the two were] somehow fundamentally different. It's not different. But it's trapped an entire generation."

In his remarks, Biden highlighted the work he did with President Barack Obama to help curb sentencing disparity for crack versus powder cocaine.