Many have linked the disparity to a deliberate prosecution to "round-up" those in the African American community. The stereotype has been that Americans plagued with a lesser economic disposition are more liable to use the less expensive crack cocaine than it's more expensive counterpart, powder cocaine. "What was clear was that the rules disproportionately affected African-Americans, leading civil rights leaders and other public officials to level harsh criticism against the criminal justice system. That's why in 2010 Congress passed and the Barack Obama signed the Fair Sentencing Act which lowered the sentencing ratio of crack to powder crimes from 100:1 to 18:1." See "Inmates Set for Release After Changes in Crack Sentencing" by Gabriel Roxas
Now the U.S. Sentencing Commission is applying that law to past cocaine convictions. Officials estimate about 12,000 inmates could eventually benefit.