Since the late 1990s, states asserted immigration oversight under immigration federalism; it was determined that the federal government had supremacy on immigration in a 2012 Supreme Court decision.

• A. United States v. Nixon
• B. Printz v. United States
• C. Arizona v. United States
• D. Reno v. Condon

Answer: (C)

The main idea here is that immigration policy is under federal supremacy; states can cooperate, but they cannot override or create their own independent enforcement regime. In the 2012 Supreme Court decision, the Court reviewed Arizona’s SB 1070, a sweeping state attempt to police immigration. The Court struck down several provisions as preempted by federal law, reaffirming that the federal government has the primary authority to regulate who may enter, stay in, or be removed from the country. The ruling makes clear that states cannot unilaterally expand immigration enforcement or create state offenses based on immigrant status, even as they may assist or enforce existing federal rules within constitutional limits. Other cases you might have seen deal with different areas of federal vs. state power, but this decision specifically established federal supremacy in immigration.