What standard should appellate courts use to review claims of substantively unreasonable sentences under 18 U.S.C. § 3553(a)?

QUESTIONS PRESENTED L 18 U.S.C. § 3553(a) states: “The court shall impose a sentence sufficient, but not greater than necessary.” Indeed, there are factors found in § 3553(a)(2) that sentencing courts must consider, but nothing concrete that defines this ambiguous mandate. The discretion to impose a sentence sufficient, but not greater than necessary, is left to each individual judge across the country. When appellate courts tackle claims of substantively unreasonable sentences, there is no guidance from Gall, Rita, Booker, or other cases on how to review such claims and many, if not all, cases are “rubber stamped” as affirmed. Mr. Bowen asks this Court to clarify this novel issue. i