ABSTRACT
In the federal system of the United States of America, the national government and the state governments each have a direct relationship with the electorate. Federalism emerges from the US Constitution as one of the core concepts of US government and politics. In a federal system there is a central government and a layer of sub-national governments. Both elements derive their power directly from the citizens and exercise authority directly over the population that elected them. In the scholarship on federalism there are a number of concepts that compete to encapsulate the relationship between the federal and state governments. A distinction is commonly drawn between dual federalism, a model said to apply to the whole period from America's founding to the early twentieth century, and cooperative federalism, covering roughly the last century, and sometimes subdivided into shorter periods.
