Federalism is a system of government in which a territory is managed by two levels of government. The central government oversees the issues that affect the whole country, and the small subdivisions oversee the issues of local concern. Both the central government and the smaller subdivisions or the regional governments have the powers to make and enact laws. The two levels of governments also have independence from each other. Canada, Brazil, USA and Australia practice a federal system of governance.
The US has a federal structure of government which consists of the federal or the national government, and the governments of individual states. Each state has its political significance or own position of legal autonomy. Although the states are not sovereign bodies, they do not exercise powers carried out by the national government. Both levels of governments have exclusive powers and share other powers. The constitution of the United States grants the national government with the powers over matters of national concern while the state governments have jurisdiction over matters of domestic concern.
While the National government in the US can enact laws regarding the whole country, its powers are limited or remunerated. For example, the national government can regulate the commerce between states pursuant to the “Commercial clause” in the constitution, but it cannot regulate commerce taking place only within one state. Each of the 52 states in the United States has its own constitution; however, it must comply with the federal constitution. For example, a constitution of any state cannot deny criminals the right to a jury trial as assured by the 6th amendment of the U.S. constitution. If the State constitution is inconsistent with the Federal constitution, then the Supreme Court will proclaim it unconstitutional.