Whether, in a § 846 prosecution for conspiracy to violate § 841, a trial court errs if it fails to correctly instruct the jury on the elements of the § 841 offense

21 U.S.C. § 846 makes it a crime to “ conspire [] to commit any offense defined in this subchapter .” Prosecutors frequently seek to prove a § 846 violation — as they did in this case —by proving that the defendants conspired to violate 21 U.S.C. § 841, which makes it a federal crime, “[e]xcept as authorized[,] . . . for any person knowingly or intentionally . . . to manufacture, distribute, or dispense . . . a controlled substance.” 84 Stat. 1260, 21 U. S. C. § 841(a) . A core tenet of conspiracy law is that “the failure of the trial court to instruct the jury on the elements of the substantive crimes constituting the objects of the charged conspiracy ” is a “serious error.” United States v. Martinez , 496 F.2d 664, 669 (5th Cir. 1974) ; acco rd United States v. Alghazouli , 517 F.3d 1179, 1189 (9th Cir. 2008) . And in the Fourth and Tenth Circuit s that is the rule for § 846 conspiracies. Th ey hold that a § 846 conviction on a § 841 theory requires the jury to be correctly instructed as to the elements required to violate § 841. But t he Fifth and Eleventh Circuits do not require that . In the decision below, the Eleventh Circuit, in an unpublished opinion, for at least the fourth time, refused to hold that a person cannot be convicted under 21 U.S.C. § 846 for conspiring to violate § 841 unless the jury is correctly instructed as to the elements of § 841. Judge Jordan concurr ed. Eleventh Circuit precedent required him to vote to affirm, he explained, but “ writing on a clean slate ” he “ would find the Tenth Circuit ’s contrary decision in United States v. Kahn , 58 F.4th 1308, 1311 (10th Cir. 2023), more persuasive. ” The question presented is: Whether , in a § 846 prosecution for conspiracy to violate § 841, a trial court errs if it fails to c orrectly instruct the jury on the elements of the § 841 offense . (ii)