In the case of Shular v. United States, 2019, Eddie Lee Shular challenged his sentence enhancement under the Armed Career Criminal Act (ACCA). The ACCA imposes a mandatory minimum sentence for individuals convicted of firearm possession who have three or more prior convictions for serious drug offenses or violent felonies. Shular argued that his six previous Florida state law convictions did not qualify as "serious drug offenses" because they did not involve conduct specified in the federal Controlled Substances Act (CSA). However, the Supreme Court ruled against him unanimously. They held that a crime qualifies as a “serious drug offense” under ACCA if it involves conduct specified in clause (ii) of CSA’s definition of a “felony drug offense,” regardless whether it also involves conduct specified in clause (i), which requires proof of distribution or intent to distribute drugs. Therefore, even though Shular's previous crimes were simple possessions without any intention to sell or distribute drugs, they still counted towards enhancing his current conviction.

In the dissenting opinion for Shular v. United States, Justice Sotomayor argued that the majority's interpretation of 18 U.S.C. §924(e)(2)(A) was too narrow and inconsistent with Congress' intent to target repeat offenders of serious drug offenses. She contended that the statute should be read more broadly to include state-level convictions as predicate offenses if they involve conduct that would constitute a federal offense under the Controlled Substances Act (CSA). According to her, this approach is consistent with both statutory text and precedent which emphasizes substance over form in determining whether a prior conviction qualifies as an "offense" under federal law. Furthermore, she criticized the majority’s reliance on Taylor v. United States because it failed to consider important differences between ACCA’s elements clause and its definition of “serious drug offense.” Finally, she expressed concern about potential disparities in sentencing outcomes due to variations in state laws.