Final answer:
The Supreme Court ended the traditional system of federalism through rulings that limited the national government's power, such as the case of United States v. Lopez.
Step-by-step explanation:
The Supreme Court ended the traditional system of federalism through a series of rulings that limited the scope of the national government's power. One notable case is United States v. Lopez, where the court struck down the Gun-Free School Zones Act of 1990, arguing that it did not affect interstate commerce. This ruling marked the end of a period where the court had a broad interpretation of the commerce clause, allowing it to regulate local commercial activities.