Does the contention that the Guidelines violate the ex post facto clause in the United States Constitution need to be considered as an alternative ground for reversing the District Court's decision?

After oral argument, the contention that the Guidelines violate the United States Constitution's ex post facto clause was raised as an alternative ground for reversing the district court. In light of the fact that we dispose of this case on a statutory ground, we need not reach the constitutional argument. See Califano v. Yamasaki, 442 U.S. 682, 692-93, 99 S.Ct. 2545, 2553-54, 61 L.Ed.2d 176 (1979) ("A court presented with both statutory and constitutional grounds to support the relief requested usually should pass on the statutory claim before considering the constitutional question. Due respect for the coordinate branches of government, as well as a reluctance when conscious of fallibility to speak with our utmost finality, counsels against unnecessary constitutional adjudication.") (citations omitted).