With states like Utah, Arizona and New Jersey passing their own patchwork set of laws to deal with the nation’s burgeoning illegal immigration problem, sometimes the question is begged: Do these State’s even have such authority? Many immigration lawyers would argue that these state laws are per se preempted.
The Commerce Clause of the Constitution authorizes the U.S. Congress to regulate commerce with foreign nations and also between states. The Naturalization Clause empowers the Legislature to establish a uniform rule of citizenship. This has been interpreted to mean that the rules of citizenship and naturalization has to apply uniformly to all the states.
The Migration and Importation Clause constricts the migration or “importation” (referring to slaves, sadly) of persons into the U.S. Finally the last commonly cited example of enumerated constitutional powers over immigration is Congress’ war power. The so called “War Power Clause” of the Constitution gives Congress the power to declare war and also permits the U.S. government to stop the entry of illegal aliens and to remove them from the country.
There are also so-called implied constitutional powers given to Congress to govern immigration issues. For example, in the famous Chinese Exclusion Case in 1889, the Supreme Court found that the power to exclude aliens is “an incident to sovereignty … essential to self-preservation, to forbid the entrance of foreigners within a country’s dominion, or to admit them in only such cases and upon such conditions as it may see fit to prescribe.