A Massachussetts federal judge has declared the Federal Sentencing Guidelines unconstitutional:

In a scathing criticism of the system used to punish federal crimes, a judge on Monday called the government's sentencing guidelines unconstitutional, saying they unfairly limit the authority of judges. In a series of drug cases, U.S. District Judge William Young said the guidelines put too much power in the hands of prosecutors and give judges too little discretion in sentencing.

....In his ruling, Young said he believes the sentences handed down to five defendants were too harsh and violated their constitutional right to due process. Young asked the 1st U.S. Circuit Court of Appeals to throw out the sentences and send the cases back for new sentencing hearings.

Judge Young is not the only Judge to harbor such beliefs:

....many judges have lamented the stringent nature of the guidelines, and some judges have refused to take criminal cases because they object so strenuously to the rules."What judges have perhaps most strongly detested has been exactly what Judge Young says here, and that is that the Department of Justice acts, in a manner of speaking, as both prosecutor and executioner," Yas said.

As we point out here, the Guidelines came in under former President Ronald Reagan ...as did mandatory minimum sentences, laws allowing the death penalty for drug kingpins and the Bail Reform Act, which allowed Judges to deny bail for many drug defendants at the request of prosecutors.

Update: Judge Young's sentencing opinion describing "the reality of criminal sentencing under the Guidelines" (op.p.59) and holding that "the Guidelines system violates the constitutional rules announced in
Apprendi v. New Jersey and Ring v. Arizona" (id.) is 176 pages in length and can be found here. If that fails, go to the district court website, click on case information, opinions, recent opinions and then United States v. Green.