From our colonial origins to our Constitution and beyond, Americans have found ways to unite. The nature of the Union is unique, however. Unlike the sovereign European monarchies of the 17th to 20th centuries that ruled the people as subjects, it is not a totalizing or consummate proposition. Rather, American unity formed around We the People-approved agreements, granting governments limited powers and responsibilities, and preserving valuable local independence and autonomy.
For almost 170 years, from the Mayflower Compact in 1620 to the Constitution in 1787 — first as colonists and later as Americans — our predecessors experimented with this form of unity. The Constitution is the culmination of this idea with its “compound republic” or federal system of government.

While the Constitution never specifically mentions the term federalism, it is inherent in the structures and processes created by the Constitution. For example, the Constitution grants limited and enumerated powers to the national government and affirms that other powers belong to the states. States are guaranteed a “republican (representative) form of government;” they may not be divided without their consent; they are responsible for elections; and they play a fundamental role in the structure of the Senate, the election of the president and the passage of constitutional amendments. The supremacy clause ensures that in conflicts between national and state laws, national laws prevail if those laws are consistent with the Constitution. In essence, federalism is a fundamental component of the Constitution.
Yet there is considerable ambiguity in the boundaries between national and state governments. Constitutional components like the Commerce Clause and the Necessary and Proper Clause mean that American federalism is not built on an absolute and rigid separation of powers between the nation and the states.
The Constitutional Convention in 1787 rejected many proposals to limit national power, including an effort to prohibit any constitutional amendment that would limit states’ police powers. In the congressional debates over the Bill of Rights, an amendment to limit the national government’s powers to those “expressly” delegated was rejected. Many founders, including James Madison and Roger Sherman, a strong advocate for states, acknowledged that drawing a clear line between national and state powers and responsibilities is nearly impossible.
The American federal system, in short, is based on an essential and unalterable core, but it is not limited to the nineteenth-century institutions that attempted to rigidly separate national and state powers. Rather, the American federal system is dynamic and adaptable, hence capable of multiple permutations consistent with that unalterable core.
Today, nearly 40% of the world’s population lives under a federal form of government. Yet federalism is often misunderstood and maligned. Some equate federalism with racism, segregation and slavery. Others think federalism means states’ rights. Neither is accurate. Federalism’s core purpose is to protect and preserve the foundational American value of self-government at the national, state and local levels. It does this by protecting minority rights and liberties while establishing a strong national government that can provide safety, security and a common market.
Federalism emerges from the desire to be both united in some things and autonomous in others. It is a compromise between contrasting desires to be big enough to fulfill a common interest (such as to deter outside aggressors or create a market economy) and the desire to preserve the liberties that come from being small, local and autonomous. Sustaining that tension is difficult because the “natural tendency of any political community, whether large or small, is to completeness, to the perfection of its autonomy” (Martin Diamond, “The Ends of Federalism”). Sustaining a federal union requires accepting the tension that arises from balancing unity and multiplicity.
Some falsely think multiplicity causes disunity. Unity need not mean uniformity, unanimity or even agreement. Unity can form over commitments to address common problems by following established procedures or to let each be if certain rules and values are respected (Yuval Levin, “American Covenant”). Constitutional federalism provides an institutional framework for resolving collective and common problems that does not require uniformity but respects and values differences and diversity.
Our constitutional federal union allows shared rule (as a nation) and self-rule (as states, local communities, families and individuals). As Yuval Levin notes in “American Covenant,” recalling our shared values and restoring the federal agreement of shared rule and self-rule may be key to preserving our unity and union.