Final answer:
The Dormant Commerce Clause has been the center of cases like United States v. Lopez, which struck down the Gun-Free School Zones Act, and United States v. E. C. Knight, limiting federal authority over manufacturing, exemplifying the restrictions on Congress's powers under the commerce clause.
Step-by-step explanation:
Class examples of cases that have been considered as violations of the Dormant Commerce Clause include United States v. Lopez (1995) and United States v. E. C. Knight (1895). In United States v. Lopez, the Supreme Court struck down the Gun-Free School Zones Act of 1990 as it did not substantially affect interstate commerce, marking a significant shift in the Court's interpretation of the commerce clause. Similarly, in United States v. E. C. Knight, the Court ruled that manufacturing was not within the scope of the commerce clause, thereby limiting federal authority over manufacturing processes which were considered local activities.