Because federalism is a compound form of government, combining a general government with regional governments, the constitutional principle of federalism is seen in the amendment process through state involvement. Amendments are proposed in Congress and are ratified (or not ratified) by the states. Another example is the ability for the states to propose a constitutional amendment, as they can call for a constitutional convention if two-thirds of state legislatures are in agreement. This has never happened before, but it is possible under the Constitution.
