This dynamic is another reason to repeal mandatory sentencing laws, which have proved disastrous across the country, helping fill up prisons at a ruinous cost. These laws were conceived as a way to provide consistent, stern sentences for all offenders who commit the same crime. But they have made the problem much worse. They have shifted the justice system’s attention away from deciding guilt or innocence. In giving prosecutors more leverage, these laws often result in different sentences for different offenders who have committed similar crimes.

Mandatory minimums have created other problems. As the United States Sentencing Commission concluded, such sentences have fallen disproportionately on minorities. African-Americans recently made up 24 percent of the federal prison population but 33 percent of those given mandatory minimum sentences. Excluding immigration cases, Hispanics accounted for 30 percent of the prison population but almost 40 percent of such sentences.

These laws have helped fill prisons without increasing public safety. In drug-related crime, a RAND study found, they are less effective than drug treatment and discretionary sentencing.

The American Bar Association, the Judicial Conference of the United States and every major organization focusing on criminal justice opposes mandatory minimum sentences. The federal and state governments should get rid of them — and the injustices they produce.