Solomon Chamu v. U.S. Attorney General, 23 F.4th 1325

Solomon Chamu, a Mexican national who entered without inspection, was convicted in 2003 under Florida Statute §893.13(6)(a) for cocaine possession and later placed in removal proceedings.
He applied for cancellation of removal, which is barred for aliens convicted of an offense “relating to a controlled substance (as defined in section 802 of title 21).”
Chamu argued his Florida conviction should not bar relief because (1) Florida’s statutory definition of “cocaine” (including "stereoisomers") is broader than the federal definition (which lists "optical and geometric isomers"), and (2) Florida’s possession law lacks an explicit illicit‑nature mens rea.
The Board of Immigration Appeals accepted the expert declaration’s chemical generalities for argument’s sake but found no realistic probability Florida would prosecute possession of a cocaine isomer that falls outside the federal schedules and treated the mens rea point as irrelevant to the immigration statute.
The Eleventh Circuit applied the categorical approach, held Chamu bore the burden to show a realistic probability of broader state prosecution, found the record lacked evidence that a noncovered cocaine stereoisomer actually exists or has been prosecuted, and concluded Florida’s conviction bars cancellation.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Florida’s definition of “cocaine” is broader than the federal definition such that a conviction would not "relate to a controlled substance" under federal law	Florida’s statute covers all stereoisomers; federal law covers only optical and geometric isomers, so some stereoisomers (nongeometric diastereomers) could be outside federal coverage	There is no realistic probability Florida would prosecute possession of a cocaine stereoisomer that is not a federally controlled substance; Chamu offers no record evidence such an isomer of cocaine exists or has been prosecuted	Held: Plaintiff failed to show realistic probability of broader prosecution; record lacks evidence of noncovered cocaine isomers, so conviction relates to a federally controlled substance
Whether Florida’s possession statute lacks an illicit‑nature mens rea and thus cannot trigger immigration consequences	Florida’s statutory scheme presumes knowledge differently than federal law, so the state offense is not congruent with the federal comparator and cannot trigger removal consequences	The immigration statutes target convictions "relating to a controlled substance" (a physical object), not a generic offense element set; the statutes do not incorporate an illicit‑nature mens rea to be compared	Held: Mens rea is irrelevant to the immigration criterion here; no illicit‑nature mens rea is required to trigger immigration consequences

Gonzales v. Duenas‑Alvarez, 549 U.S. 183 (2007) (requires showing a realistic probability, not a theoretical possibility, that a state statute covers conduct beyond the federal comparator)
Ramos v. U.S. Att’y Gen., 709 F.3d 1066 (11th Cir. 2013) (statutory text can suffice to show realistic probability when language itself creates divergence)
Kawashima v. Holder, 565 U.S. 478 (2012) (explains categorical approach and reviewing statute defining the crime of conviction)
Shular v. United States, 140 S. Ct. 779 (2020) (distinguishes offense‑based categorical comparison from comparisons asking whether convictions meet another statutory criterion)
Mellouli v. Lynch, 575 U.S. 798 (2015) (immigration statutes can target conduct involving a controlled substance as a physical object)
Guillen v. U.S. Att’y Gen., 910 F.3d 1174 (11th Cir. 2018) (addressed divisibility of Florida possession statute by substance identity)
Alexis v. Barr, 960 F.3d 722 (5th Cir. 2020) (refused to find Texas cocaine definition broader absent sample prosecutions)
United States v. Rodriguez‑Gamboa, 972 F.3d 1148 (9th Cir. 2020) (held differing statutory isomer language insufficient where disputed isomers do not chemically exist)
Donawa v. U.S. Att’y Gen., 735 F.3d 1275 (11th Cir. 2013) (discussion of mens rea as an element in categorical comparisons)
Kazemzadeh v. U.S. Att’y Gen., 577 F.3d 1341 (11th Cir. 2009) (substantial‑evidence standard for reviewing the BIA)