Crack cocaine offenders are typically sentenced to 50 percent more jail time than powder cocaine offenders. This sentencing disparity emerged in the mid Eighties, when lawmakers mandated harsh sentences in response to the country's cocaine epidemic. Fast forward to today: Experts now know that there's little difference between crack and powdered cocaine, but crack offenders are still serving harsher sentences than powdered offenders. Yesterday the United States Sentencing Commission, which puts out sentencing guidelines for federal judges to follow, narrowed that disparity for as many as 19,500 prison inmates. The decision will reduce sentences for hard cocaine users by an average of 27 months, and it applies retroactively. Predictably, the Commission's decision has stirred up a lot of controversy: some argue that it will put criminals back into fragile neighborhoods already marred by crime, others argue that it will eat up time and money from the federal courts, and still others argue that the Commission should go even further in reducing the sentencing disparity.