Via the National Academies of Sciences, here is our best estimate of the historical incarceration rate in America:
As you can see, the 1994 crime bill had no effect on this trend. Incarceration rates started skyrocketing in the late 70s as a response to rising crime rates, and after the crime bill passed the increase in incarceration started to slow, eventually peaking in 2000.
The crime bill, of course, deserves credit for slowing incarceration no more than it deserves blame for increasing it. It was a null factor. Incarceration increased as crime rates increased, and then started to fall about a decade after crime rates started to decline. Mass incarceration in the US was a panicked response to mass crime, and the 1994 crime bill had little effect on it one way or the other.
I don’t really care what anyone thinks of Joe Biden, but liberals should stop inventing reasons to blame him for things he isn’t responsible for. The 1994 crime bill (a) included a lot of good ideas, (b) included some bad ideas at the insistence of Republicans, (c) had nothing to do with skyrocketing incarceration rates, (d) was supported by most black lawmakers, and (e) was a reaction to the fact that violent crime really was high, and nobody at the time had any reason to think this was likely to change.
