Whether the commentary can add conspiracy and other inchoate offenses not included in the guideline definition of 'controlled substance offense'

QUESTION PRESENTED The United States Sentencing Guideline Career Offender provision—which has been applied to eleven percent of the Bureau of Prisons inmate population— clearly and unambiguously defines the term “controlled substance offense” for the purpose of that guideline by identifying the substantive offenses that qualify. In commentary, the United States Sentencing Commission expands that definition by adding inchoate offenses, including conspiracy. The courts of appeals are split: some defer to the commentary’s expansion of the Guideline, others contend that the language of the Guideline specifies the offenses that qualify for career offender treatment, leaving no room for deference to the commentary. In Kisor v. Wilkie, —U.S. —, 139 S. Ct. 2400 (2019), this Court held “the possibility of deference [to an agency interpretation of its rules] can arise only if a regulation is genuinely ambiguous... after a court has resorted to all the standard tools of interpretation.” Most circuits have not applied this standard to assessments of whether deference is due to Guidelines commentary. The Question Presented is: When “controlled substance offense” is defined in the text of the Career Offender Guideline, U.S.S.G. § 4B1.2(b), whether the commentary can add conspiracy and other inchoate offenses not included in the guideline definition? i