What system divides power between the national and state governments?

Federalism is the system that divides power between the national and state governments. This structure is foundational to the United States Constitution, which allocates certain powers to the federal government while reserving others for the states. Federalism allows for a balance where the national government can handle issues that affect the entire nation, such as defense and foreign affairs, while state governments address local matters, such as education and law enforcement.

This division of power enables both levels of government to operate independently within their respective spheres while still cooperating on shared responsibilities. It promotes diversity in governance, as states can enact laws that reflect their unique populations and needs, leading to a more tailored approach to governance. Federalism also serves as a system of checks and balances, preventing any one level of government from becoming too powerful.

The other systems mentioned, like a unitary system, where power is concentrated in a central government, or a confederation, where independent states have most of the power with a weak central authority, do not provide for this balanced power division. Oligarchy refers to a system where power is held by a small group of people, which is not relevant to how power is structured between national and state governments.