A small-time crack dealer and a decorated military veteran who lied to a grand jury went before the U.S. Supreme Court this week to test the boundaries of federal judges’ sentencing discretion in a world where the Federal Sentencing Guidelines are no longer mandatory.

With Claiborne v. U.S., No. 06-5618, and Rita v. U.S., No. 06-5754, argued Tuesday, the justices have their first opportunity to tell trial and appellate judges how much weight to give the now-advisory guidelines whose mandatory nature the high court in 2005 found constitutionally invalid in U.S. v. Booker, 543 U.S. 220.