Foreigners Generally Suppose that the State Governments Are Subordinate to the Federal, But This Is Not the Case; States Are the Domestic and the Federal the Foreign Branch of the Same Government

With respect to our State and federal governments, I do not think their relations correctly understood by foreigners. They generally suppose the former subordinate to the latter. But this is not the case. They are co-ordinate departments of one simple and integral whole. To the State governments are reserved all legislation and administration, in affairs which concern their own citizens only, and to the federal government is given whatever concerns foreigners, or the citizens of other States; these functions alone being made federal. The one is the domestic, the other the foreign branch of the same government; neither having control over the other, but within its own department.

--Thomas Jefferson, The Political Writings of Thomas Jefferson, ed. Merrill D. Peterson (Charlottesville, VA: Thomas Jefferson Foundation, 1993), 210.