Ramon Belducea-Mancinas was sentenced as a career offender based on pre-2018 federal convictions for conspiracy to distribute marijuana. In December 2018, Congress narrowed the definition of marijuana to exclude hemp. The Fifth Circuit already defined "controlled substance" in the Sentencing Guidelines as a substance controlled by the federal Controlled Substances Act. Yet, the court of appeals held the error was not plain because the court had not decided this precise question. Had Belducea been prosecuted in the Ninth Circuit, the error would have been deemed plain.

The question presented is:

Is it obvious error to find a prior federal drug trafficking conviction is a "controlled substance offense" under the Sentencing Guidelines when the substance trafficked is not, at the time of sentencing, categorically a federally controlled substance?

Is it obvious error to find a prior federal drug trafficking conviction is a 'controlled substance offense' under the Sentencing Guidelines when the substance trafficked is not, at the time of sentencing, categorically a federally controlled substance?