Last Friday, President Obama wrote 46 letters to men and women across the United States that will change their lives. “Dear Jerry,” Obama wrote to one man, “I wanted to personally inform you that I will be granting your application for commutation.” Jerry, like the others, is a convicted drug offender who, Obama claims, should long ago have served his time and been released back into society. Instead, tens of thousands of other low-level drug offenders continue to fester in federal prison; the consequence of overzealous, 1980s-era mandatory minimum sentencing requirements that have led to dangerous overcrowding in the federal...