The Supremes have shot down federal manditory sentences which have for years placed drug offenders in prison for longer terms than violent criminals:

The justices, ruling 5-4 in two drug cases, said the guidelines violate the constitutional jury-trial right by forcing judges to increase the range of possible sentences based on their own factual findings. By a separate 5-4 majority, the court said the guidelines will no longer be mandatory for judges and instead will be “effectively advisory.”

[…]

The cases are U.S. v. Booker, 04-104, and U.S. v. Fanfan, 04- 105.

Expect those convicted of drug offenses, as well as white-collar criminals, to swamp the courts with motions for sentence reconsideration. Also, expect Congress to draft up some new way to “get tough”:

“Ours, of course, is not the last word,” Breyer wrote. “The ball now lies in Congress’s court.”