The Sentencing Reform Act of 1984 provided that the trial court "shall impose a sentence of the kind, and within the range" set forth in the United States Sentencing Guidelines ("Guidelines") issued by the Sentencing Commission. With that one phrase, the Act created a system of guidelines that was binding upon judges, rather than simply advisory. Concerns about excessive disparity and undue leniency in sentencing unquestionably drove the political coalition that passed the Act. It is not clear, however, why Congress believed that mandatory-as opposed to advisory-guidelines were necessary to address those concerns. With the benefit of hindsight, it is apparent that mandatory guidelines were unnecessary in 1984. Indeed, more than a year of experience under a regime of advisory guidelines, put in place by the Supreme Court in United States v. Booker, reveals that advisory guidelines effectively prevent both disparity and leniency-related problems. Unfortunately, just as Congress failed to give meaningful consideration to the adequacy of advisory guidelines some twenty years ago, it now seems determined to make the same mistake.