No, Joe Biden Didn’t Cause Mass Incarceration

Over at Vox, Tara Golshan writes this:
Ahead of the debate, Booker signaled he planned to attack the former vice president over his role in the 1994 crime bill, which Biden helped write and, as Vox’s German Lopez has reported, experts now see as one of the major contributors to mass incarceration in the 1990s.
Huh. Did Lopez really say that? Let’s click and find out:

The 1994 law didn’t really cause mass incarceration
….That’s reflected in the statistics, which show that incarceration rates were climbing rapidly before the 1994 crime law and actually started leveling off a few years after.

Incarceration rates approximately quadrupled between 1970 and 1994, and flattened almost immediately thereafter. The 1994 crime bill simply didn’t have anything to do with it.
I realize this is politically impossible, but sometimes I wish Joe Biden would just flat out defend the 1994 bill. “You know what happened after that bill passed?” he should ask. “Crime went down, that’s what.” This would be pretty misleading since we all know what really caused the crime decline,¹ and it’s unlikely the 1994 bill had much impact on its own. Still, it’s at least a true statement.
¹The phaseout of leaded gasoline. But you already knew that, right?