Attorney General Merrick Garland moved Friday to end sentencing disparities that have imposed harsher penalties for different forms of cocaine and worsened racial inequity in the U.S. justice system.For decades federal law has imposed harsher sentences for crack cocaine even though it isn’t scientifically different from powder cocaine, creating “unwarranted racial disparities,” Garland wrote in a memo. “They are two forms of the same drug, with powder readily convertible into crack cocaine …