Whether a criminal defendant is entitled to relief under a retroactive constitutional decision invalidating a federal statutory provision, where the record is silent on the basis of the original judgment

QUESTION PRESENTED Whether, or under what circumstances, a criminal defendant pursuing a second or successive motion under 28 U.S.C. § 2255 is entitled to relief under a retroactive constitutional decision invalidating a federal statutory provision, where the record is silent as to whether the district court based its original judgment on that provision or another provision of the same statute.