What is a power that only the federal government holds?

The power to declare war is a power that is exclusively reserved for the federal government in the United States. This authority is established in the U.S. Constitution, specifically within Article I, Section 8, which grants Congress the ability to declare war. This power is critical for maintaining a unified national defense and ensuring that military actions are taken with the consent of the legislature representing the entire country.

In contrast, taxation is a power that is shared between federal and state governments; both levels can impose taxes. Establishing local governments is a power that resides primarily with state governments, as they have the authority to create and regulate localities within their jurisdiction. Conducting elections is also primarily the responsibility of state governments, which manage state and local electoral processes. Thus, the declaration of war is distinctly a federal power, highlighting the specific role of the federal government in national defense.