Does the unique ACCA occasions-different inquiry render Erlinger error structural, and what is the proper harmless-error review test for a guilty plea case?

This case presents two important questions that impact countless defendants and have divided circuit judges. After Gerald Campbell pled guilty to being a felon in possession of a firearm under 18 U.S.C. § 922(g)(1), the district court determined, by a preponderance of the evidence, that his prior offenses qualified as different occasions under the Armed Career Criminal Act, 18 U.S.C. § 924(e) (“ACCA”), and accordingly sentence him to serve a mandatory minimum sentence of 15-years’ incarceration. After Erlinger v. United States , 602 U.S. 821 (2024), the Sixth Circuit agreed that the district court erred by making the occasions-different finding itself, but found the error was harmless by relying upon Shepard1 documents presented at Mr. Campbell’s sentencing. Multiple judges in the Sixth Circuit have questioned whether applying harmless-error review to Erlinger error comports with the Sixth Amendment. And, the circuits are divided as to the proper analysis in a guilty plea case, should harmless-error review apply. The questions presented here are: (1) Does the unique ACCA occasions-different inquiry, requiring a detailed, multi-factored analysis of the facts surrounding at least three prior offenses—facts which are not intrinsic to the elements of § 922(g)(1)—render Erlinger error structural? (2) If harmless-error review applies to a fully preserved Erlinger error, what is the proper test when the defendant pleads guilty to only the lesser offense under § 922(g)(1)? These are questions of exceptional importance, and this case presents an ideal opportunity for the Court to provide much-needed clarity. 1 As defined in Shepard v. United States , 544 U.S. 13 (2005).