The Obama administration is backing calls to lower the mandatory minimum prison sentence for dealing crack cocaine to match the punishment for dealing powder cocaine. Under current law, possession of five grams of crack cocaine triggers the same mandatory minimum sentence as possession of 500 grams of powder cocaine. The disparity has disproportionately punished African American drug offenders, who account for more than 80 percent of crack cocaine cases. Wednesday’s announcement marked the first time the White House has backed calls to lower minimum drug sentences.