Does 18 U.S.C. § 2422(b) require proof of a specific predicate offense?

Questions Presented 1. Does 18 U.S.C. § 2422(b), which criminalizes the attempted enticement of a minor to engage in “sexual activity for which any person can be charged with a criminal offense,” include an element requiring the government to charge and prove that the object sexual activity would violate a particular predicate offense, or is the specific predicate offense merely a means of satisfying the § 2422(b) charge? 2. Regardless of whether the predicate offense is itself an element of § 2422(b), does a Court of Appeals constructively amend an indictment in violation of the Fifth Amendment by sustaining a § 2422(b) conviction based on a different predicate offense than the one that was in fact specified in the indictment and upon which the defendant was actually convicted at trial? i