by Rob Natelson

Is the Immigration Bill Unconstitutional?

Many “progressive” opponents of the Arizona immigration law are arguing that the law is unconstitutional because foreign affairs is exclusively the province of the federal government.

That foreign affairs is exclusively the province of the federal government is commonly asserted. But it is a myth – at least if one respects the Constitution’s text and original understanding.

Before explaining why, I have to say that a claim that the Constitution reserves powers exclusively for one level of government is an unusual argument for “progressives” to make. In general, of course, the most vocal “progressives” could care less about what responsibilities the Constitution assigns to what levels of government.

It’s not just that they favor the federal government invading the sphere that the Constitution reserves to the states. It’s also that they have repeatedly urged state and local governments to invade the supposedly exclusive sphere of the federal government. Remember all those campaigns for state and local governments to adopt nuclear-freeze resolutions, South Africa boycotts, and nuclear-free zones?

Anyway, let’s move beyond the limitless subject of political hypocrisy to describe just how the Constitution does distribute foreign affairs authority.

First, the Constitution gives the federal government supreme authority over foreign policy. Congress and the President can pre-empt an issue by exercising one or more of their enumerated powers. If Congress dislikes a state action in that realm, Congress can pass a law overriding it.

If, however, Congress has not acted or acted incompletely, the states have certain reserved powers to act on their own. In other words, the Constitution acknowledges concurrent, although subordinate, state authority over foreign affairs – including immigration.

How do we know this? From both the constitutional text and from the record left by those who debated and ratified the Constitution. Here is the evidence:

* Instead of simply stating that states have no foreign affairs powers, the Constitution (Article I, Section 10) only lists a few specific foreign affairs powers denied to the states. For example, a state may not make a treaty or enter into a confederation with a foreign government.

* Under a rule of interpretation widely recognized by the Founders, the Constitution’s listing implies that all foreign affairs powers not denied remain with the states (subject to veto by federal law or treaty).

* In addition to prohibiting the states from exercising a few foreign affairs powers, the Constitution lists a few others subject to congressional pre-approval – such as the power to make non-treaty compacts with foreign governments. If foreign policy power were exclusively in the federal government, the Constitution would not recognize that states had any ability to enter compacts with foreign governments.

* Nowhere does the Constitution include language such as “all state authority over foreign relations is hereby abolished.” On the contrary, at several points the document assumes some state authority over the subject is retained. For example, the Constitution explicitly acknowledges state power to tax foreign goods to fund inspection programs. It elsewhere assumes that if Congress chooses not to adopt a “uniform Rule of Naturalization,” the states may adopt their own laws.

* The historical record confirms what the text suggests. For example, the records of the Constitutional Convention tell us that the delegates considered whether states could impose embargoes on foreign goods, and deliberately decided to leave that power with the states. A committee of the First Federal Congress recognized this power also.

The doubt about the judicial fate of Arizona’s law arises only because of the Supreme Court’s occasional practice of striking down state laws that Congress has decided to leave alone. This occurs primarily in the area of commerce and foreign affairs, and appears to be driven in part by the historically-false claim that federal power in those areas is exclusive.

On the other hand, the Supreme Court also sometimes lets such enactments stand. So what the Court would do with the Arizona law is anybody’s guess.

Rob Natelson is Professor of Constitutional Law at the University of Montana and a nationally-known expert on the American Founding. After a quarter of a century in academia, he is leaving this year to fight full-time for freedom as a Senior Fellow in Constitutional Jurisprudence at the Independence Institute in Golden, Colorado. His constitutional publications can be found at The views expressed here are his own, not to be attributed to any organization or institution.

Rob Natelson