Castaneda v. Souza, ___ F.3d ___, ___, 2014 WL 4976140 (1st Cir. Oct. 30, 2014) (Avoidance of constitutional doubt is a cardinal principle of statutory interpretation. Zadvydas, 533U.S. at 689 (quoting Crowell v. Benson, 285 U.S. 22, 62, (1932) (internal quotation marks omitted)). As the Supreme Court has explained countless times, when an Act of Congress raises a serious doubt as to its constitutionality, this Court will first ascertain whether a construction of the statute is fairly possible by which the question may be avoided. Id. (quoting Crowell, 285U.S. at 62 (internal quotation marks omitted)). This obligation requires us to attempt to find a constitutional purpose as well as a constitutional construction of the words of the statute. SKF USA, Inc. v. U.S. Customs and Border Protection, 556 F.3d 1337, 1353 (Fed. Cir. 2009). We follow that guidance here.).