Facts:  Under Sentencing Reform Act congress established U.S. Sentencing
Commission to devise guidelines to be used for sentencing in criminal cases.  The
guidelines limited judicial discretion in sentencing to cases where the judge finds specific aggravating or mitigating factors not considered by the Commission.
The seven members of the Commission are appointed by the President with advice
and consent of Congress.  At least three members must be Fed judges.  Mistretta
was indicted on Fed drug charges and challenged the constitutionality of the
guidelines.