Federalism is the system of government in which power is shared between a central government and regional governments. For example in the United States, both the national government and the state governments own a large measure of sovereignty.In addition to the separation of powers and system of checks and balances that guard against any one branch of the federal government becoming too powerful, federalism separates the powers of the federal and state governments as an added security measure to reign in government power. The federal system grants states large autonomy over lawmaking within their borders, so long as they do not violate citizens’ rights or contradict federal laws. The federal government is also able to assert power over the states through grants and mandates.
This system permits local state governments to be responsive to the particular needs of their citizens while binding the states together into a larger nation.