Final answer:
The Supreme Court's trend since the mid-1990s has been to limit the power of the national government in interpreting federalism.
Step-by-step explanation:
The Supreme Court's trend in interpreting federalism since the mid-1990s can be characterized as promoting new federalism by limiting the power of the national government. The court has narrowed the scope of the national government's power under the commerce clause, as seen in the case of United States v. Lopez. The court ruled that the Gun-Free School Zones Act of 1990 did not have a substantial impact on interstate commerce and struck it down. This represents a shift away from the broad interpretation of the commerce clause that allowed the regulation of local commercial activities in the past.