Suspect evidence informed a momentous Supreme Court decision on criminal sentencing

More than 30 years ago, Congress identified what it said was a grave threat to the American promise of equal justice for all: Federal judges were giving wildly different punishments to defendants who had committed the same crimes.
The worries were many. Some lawmakers feared lenient judges were giving criminals too little time in prison. Others suspected African-American defendants were being unfairly sentenced to steeper prison terms than white defendants.
In 1984, Congress created the U.S. Sentencing Commission with remarkable bipartisan support. The commission would set firm punishment rules, called “guidelines,” for every offense. The measure, signed by President Ronald Reagan, largely stripped federal judges of their sentencing powers; they were now to use a chart to decide penalties for each conviction, with few exceptions.
Five years later, a legal challenge to the sentencing commission wound up before the U.S. Supreme Court. In a case titled Mistretta v. U.S., the court was asked to consider whether Congress had overreached by taking on what seemed to be a role for the judiciary. In an 8-1 decision, the justices determined that the sentencing commission was constitutional. And they took care to say that the commission was also needed — to end the widespread and “shameful” sentencing disparities produced by the biases of individual judges.
Mistretta was a momentous decision, but it’s now clear the high court relied on evidence that was flimsy and even flat-out wrong.

Suspect evidence informed a momentous Supreme Court decision on criminal sentencing