In the 2014 case Johnson v. United States, the U.S. Supreme Court ruled that a portion of the Armed Career Criminal Act (ACCA) was unconstitutionally vague and violated due process rights. The ACCA imposed mandatory minimum sentences for individuals convicted of possessing firearms if they had three prior convictions for serious drug offenses or violent felonies, but its definition of "violent felony" included any crime that involved conduct presenting a "serious potential risk" to others - language which was deemed too ambiguous by the court in this ruling. This decision came after Samuel Johnson pleaded guilty to being a felon in possession of a firearm and challenged his sentencing under ACCA on grounds that his previous conviction did not qualify as one involving physical force against another person.

In the dissenting opinion for Johnson v. United States, Justice Alito argued that the majority's decision to strike down part of the Armed Career Criminal Act (ACCA) as unconstitutionally vague was a departure from precedent and an unnecessary intrusion into Congress' domain. He contended that ACCA’s residual clause had been interpreted by lower courts without significant difficulty and its meaning could be discerned through traditional methods of statutory interpretation. Furthermore, he expressed concern about potential implications on other laws with similar language which might now also be considered vague under this new standard set by the court. Lastly, he warned against judicial activism in invalidating statutes passed by Congress based on hypothetical scenarios rather than actual cases before them.