In Chapman v. United States (1991) 500 U.S. 453, the United States Supreme Court rejected a claim that arbitrary federal drug sentences violated a fundamental liberty interest, reasoning that while every person has a fundamental right to liberty in that the government may not punish him or her until it proves his or her guilt beyond a reasonable doubt in a constitutionally adequate criminal trial, "a person who has been so convicted is eligible for, and the court may impose, whatever punishment is authorized by statute for his or her offense, so long as that penalty is not cruel and unusual, , and so long as the penalty is not based on an arbitrary distinction that would violate the Due Process Clause of the Fifth Amendment." (Id. at p. 465.) The court noted that an argument based on equal protection essentially duplicates an argument based on due process. (Ibid.)