Final answer:
A system that divides authority among legislative, executive, and judicial branches practices the principle of separation of powers, which is fundamental to the U.S. government structure. It is coupled with a system of checks and balances and is extended through federalism to both national and state levels.
Step-by-step explanation:
A system that vests political, judicial, and policymaking authority in different branches of government adheres to the principle of separation of powers. This concept is fundamental in structuring a government that prevents any one branch from gaining too much power, thereby maintaining a balance. In the United States, this principle is manifested through the creation of three separate branches of government: the legislative, executive, and judicial branches, each with its own distinct responsibilities.
The legislative branch is responsible for creating laws, the executive branch for enforcing laws, and the judicial branch for interpreting laws. The separation of powers is enhanced by a system of checks and balances, where each branch has certain powers that can influence or control the other branches' actions. For instance, although the legislative branch (Congress) creates legislation, the president (executive branch) has the power to veto legislation, which can be overridden by a supermajority in Congress.
Furthermore, beneath the national level, there is a complex system of federalism, where power is also divided between the national and state governments, with each having its own executive, legislative, and judicial branches. This further extends the principle of separation of powers, ensuring a broad distribution of authority and preventing the concentration of power.