What is an example of a power denied to both state and federal governments?

Taxing imports and exports is an example of a power denied to both state and federal governments because this authority is explicitly reserved for Congress under the Constitution. Article I, Section 10 prohibits states from taxing imports and exports, while the federal government has the exclusive power to impose tariffs and regulates trade with foreign nations. This restriction ensures uniformity in trade policy and prevents states from enacting tariffs that could disrupt national economic interests or create conflicts among states.

Other options involve powers that either government does hold. For instance, enforcing immigration laws is primarily a federal responsibility, while regulating foreign trade falls under the jurisdiction of the federal government. Establishing a navy is also a federal power, specifically outlined in the Constitution, indicating that states cannot independently maintain their own naval forces. The clear division of powers helps maintain a cohesive national framework while preventing individual states from exerting separate control over crucial national interests.