Whether the Eight Circuit's decision conflicts with Burrage v. United States regarding causation

QUESTION PRESENTED FOR REVIEW This petition presents the following questions: 1. Whether the Eight Circuit's decision conflicts with the Supreme Court's opinion in Burrage v. United States, 134 S.Ct. 881 (2014), which held that when a criminal statute includes a causation element, the government must prove "but for" causation? 2. Whether 18 U.S.C. § 1591(a), which creates the substantive crime of Commercial Sex Trafficking, requires the government to prove that a commercial sex act occurred, as opposed to offenses charged under 18 U.S.C. § 1594(a) and (c), which create the inchoate crimes of attempt and conspiracy, and whether, if the statute is construed to exempt proof of a commercial sex act, does such reading seriously call into question its constitutionality as exceeding congressional authority granted by the Commerce Clause? i