Arizona v. United States (2012)

Reading:

Background Information

Understanding the facts and constitutional questions

🔗 Connecting to Our Guiding Question

When, if ever, should the government be allowed to limit a person's constitutional rights in order to protect the community?

This case asks: Should state governments be able to limit individual rights (by enforcing immigration laws) to protect their communities from illegal immigration? Consider how this case balances states' interests in protecting their communities against the federal government's exclusive power over immigration and individual rights.

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Key People in This Case

AZ
Arizona Petitioner
The State

Passed S.B. 1070, arguing the federal government wasn't doing enough to address illegal immigration. The law required police to check immigration status during stops.

US
United States Respondent
Federal Government

Sued Arizona before the law took effect, arguing that immigration is exclusively a federal responsibility and states cannot create their own immigration enforcement.

JB
Governor Jan Brewer
Arizona Governor

Signed S.B. 1070 into law in April 2010. She defended the law as necessary to protect Arizona's borders and citizens from the effects of illegal immigration.

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Civil Rights Groups
Opponents

Organizations like the ACLU opposed the law, arguing it would lead to racial profiling of Latino Americans who might be stopped simply because of how they look.

What Happened?

In April 2010, Arizona Governor Jan Brewer signed a law called S.B. 1070 to address problems related to illegal immigration. The state was facing high costs from undocumented immigrants in education, healthcare, and law enforcement, and believed the federal government wasn't doing enough to enforce immigration laws.

The Arizona law had several provisions that made it a state crime to be an undocumented immigrant, required police to check the immigration status of anyone they stopped, and allowed employers to face penalties for hiring undocumented workers.

The law sparked immediate controversy. Civil rights organizations like the ACLU argued the law would lead to racial profiling of Latino Americans, who might be stopped simply because of how they looked. Protests erupted across the country.

The federal government sued Arizona, arguing that the state law conflicted with federal immigration law. The government's position was that immigration is a federal responsibility, not a state one.

The Big Question

Can states pass their own immigration laws? Or is immigration exclusively the federal government's responsibility?

What You Need to Know

The Supremacy Clause (Article VI, Clause 2) says:

"This Constitution, and the Laws of the United States which shall be made in Pursuance thereof...shall be the supreme Law of the Land...any Thing in the Constitution or Laws of any State to the Contrary notwithstanding."

This means when federal law and state law conflict, federal law wins.

The Constitution also gives the federal government power over naturalization and foreign relations. Immigration involves relationships with other countries.

Important Facts

  • Arizona borders Mexico and has many undocumented immigrants
  • Governor Jan Brewer signed S.B. 1070 into law in April 2010
  • S.B. 1070 was nicknamed the "show me your papers" law
  • Civil rights groups like the ACLU opposed the law, fearing racial profiling
  • The law sparked nationwide protests before it even took effect
  • The federal government sued before the law took effect
  • Immigration has traditionally been controlled by the federal government
  • Arizona argued the federal government wasn't doing enough

Vocabulary

Preemption: When federal law "takes over" an area of law, preventing states from making their own conflicting rules
Federalism: The system of dividing power between the national government and state governments
Racial Profiling: When law enforcement targets people based on their race, ethnicity, or national origin rather than their behavior
Undocumented Immigrant: A person who is living in a country without legal permission or proper immigration papers

Argument Sorting Activity

Work with your group to sort these arguments

Instructions: Read each argument below and select which side it helps from the dropdown menu. When you're finished, click "Check Answers" to see your results.

The Two Sides

Argument Answer
The Constitution gives Congress the exclusive power to make immigration laws. Evidence: Article I, Section 8 gives Congress power over "naturalization" (how people become citizens). The Supreme Court ruled in Chy Lung v. Freeman (1875) that immigration is a federal power because it involves foreign relations — something only the national government can handle.
States have always helped enforce federal laws within their borders. Evidence: State and local police help enforce federal drug laws, bank robbery laws, and kidnapping laws. Under the 287(g) program, the federal government trains local officers to enforce immigration law. Arizona argued it was just helping — not replacing — federal enforcement.
Federal immigration law is so complete that it leaves no room for state laws. Evidence: The Immigration and Nationality Act (INA) is over 600 pages long and covers every aspect of immigration: who can enter, how long they can stay, how to become a citizen, and what happens if they break the rules. There's no gap for states to fill.
Arizona's law only copies existing federal requirements and doesn't create new crimes. Evidence: Federal law already requires non-citizens to carry registration documents. Arizona's Section 2(B) just required police to check immigration status — something federal law already allows. Arizona argued: "We're not making new crimes, just enforcing existing ones."
The federal government doesn't have enough resources to enforce immigration law everywhere. Evidence: In 2010, ICE (Immigration and Customs Enforcement) had only about 20,000 agents for the entire country. Arizona has 370 miles of border with Mexico. The federal government simply cannot patrol every mile — states can help fill the gap.
State immigration enforcement could interfere with America's relationships with other countries. Evidence: Mexico's government formally protested SB 1070. If each of the 50 states had different immigration policies, foreign countries wouldn't know who to negotiate with. The Constitution gives the federal government alone power over foreign affairs.
Arizona faces special problems from illegal immigration because it borders Mexico. Evidence: Arizona shares a 370-mile border with Mexico. In 2010, an estimated 460,000 undocumented immigrants lived in Arizona — about 6% of the state's population. Border states face unique challenges that states like Vermont or Maine don't experience.
Different state immigration laws would create confusing and conflicting rules across the country. Evidence: If all 50 states made their own immigration rules, someone might be legal in California but illegal in Arizona. Immigrants wouldn't know which rules to follow. Justice Kennedy wrote that immigration requires "a single sovereign" — one set of rules for everyone.
The Supremacy Clause makes federal law more important than conflicting state laws. Evidence: Article VI of the Constitution says federal law is "the supreme Law of the Land." When state and federal laws conflict, federal law wins. The Court used "preemption" — the legal term for when federal law takes over an area and blocks state laws.
States have the right to protect their borders and citizens from harm. Evidence: The 10th Amendment reserves powers to the states. States have "police powers" to protect public safety, health, and welfare. Arizona argued that protecting citizens from crime associated with illegal border crossings is a basic state responsibility.
State enforcement of immigration law could lead to racial profiling and discrimination. Evidence: Critics called SB 1070 the "show me your papers" law. The ACLU warned that police might stop people just because they "look Latino." About 30% of Arizona's population is Hispanic — many are U.S. citizens or legal residents who could be unfairly targeted.
Federal immigration priorities focus on dangerous criminals, not all undocumented immigrants. Evidence: The Obama administration's policy prioritized deporting serious criminals over families and workers. Arizona's law would force deportation of everyone — even people the federal government chose not to pursue. States can't override federal enforcement priorities.
Arizona taxpayers pay high costs for illegal immigration in schools, hospitals, and police services. Evidence: Studies estimated Arizona spent $1.6 billion per year on education, healthcare, and incarceration costs related to undocumented immigration. Arizona argued: if the federal government won't solve the problem, why should Arizona taxpayers pay the price?

Key Terms for Arguments

Important concepts to understand when debating this case

Preemption

When federal law "takes over" an area of law, preventing states from making their own conflicting rules. If state law conflicts with federal law, the state law is "preempted" and cannot be enforced.

Evidence Vault

Real sources to build your debate arguments

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Complete the Argument Sort to Unlock

Finish the sorting activity above and check your answers to access real case sources.

Welcome to the Evidence Vault! Start with the Sort Challenge below to practice interpreting facts, then analyze real case sources to build your debate arguments. You'll need at least two sources that support your side.

Analyze the Sources

Read each excerpt carefully. Decide which side of the case it supports — or if it could be used by both sides.

Legal Analysis Arizona (State)

Border Security Crisis

Arizona presented evidence of border security challenges and gaps in federal immigration enforcement that directly affected the state. SB 1070 was designed to address these security concerns.
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Analysis

Border Security Crisis

What does this show & who does it help?
This source helps Arizona. The state faces real problems from illegal immigration — crime, costs, and strain on services. When the federal government doesn't act, states should be able to protect their own citizens from these challenges.
"The Arizona v. United States Immigration Ruling." LegalClarity, legalclarity.org/the-arizona-v-united-states-immigration-ruling/.
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Legal Analysis Arizona (State)

Cooperative Federalism

Arizona argued that SB 1070 provisions were designed to work in cooperation with federal immigration law, not to conflict with it. The state claimed it was assisting federal enforcement.
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Analysis

Cooperative Federalism

What does this show & who does it help?
This source helps Arizona. The state isn't trying to create separate immigration laws — it's helping enforce existing federal law. SB 1070 mirrors federal requirements. States and the federal government can work together on shared goals.
"State of Arizona v. United States of America." Federation for American Immigration Reform, www.fairus.org/sites/default/files/2017-08/SB1070_041912.pdf.
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Government Source Arizona (State)

State Police Powers

Arizona contended that states have inherent police powers to protect their borders and citizens when federal enforcement is inadequate.
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Analysis

State Police Powers

What does this show & who does it help?
This source helps Arizona. States have always had "police powers" to protect public safety. The federal government can't be everywhere at once. States near the border have a right to use their own police to keep communities safe.
"Federal Preemption and State Authority to Deter the Presence of..." Congress.gov, www.congress.gov/crs-product/R48525.
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Legal Analysis Arizona (State)

Public Safety Concerns

The state presented evidence that illegal immigration created public safety issues that required state-level response when federal resources were insufficient.
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Analysis

Public Safety Concerns

What does this show & who does it help?
This source helps Arizona. Arizona showed real public safety issues — drug trafficking, human smuggling, violent crime. The federal government doesn't have enough agents to handle everything. States must be able to protect their residents.
"Arizona SB 1070: What Parts Are Still Enforceable Today?" LegalClarity, legalclarity.org/arizona-sb-1070-what-parts-are-still-enforceable-today/.
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Academic Federal Gov't

Federal Preemption Doctrine

The Justice Department argued that SB 1070 was preempted by the Immigration and Nationality Act (INA) because the state law conflicted with the comprehensive federal immigration scheme.
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Analysis

Federal Preemption Doctrine

What does this show & who does it help?
This source helps the Federal Government. Under the Supremacy Clause, federal law "preempts" (overrides) state laws that conflict with it. Immigration is a complete federal system — there's no room for 50 different state versions of immigration law.
"Discrimination, Preemption, and Arizona's Immigration Law." Stanford Law Review Online, review.law.stanford.edu/online/discrimination-preemption-and-arizonas-immigration-law/.
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Legal Analysis Federal Gov't

Foreign Policy Interference

The federal government argued that SB 1070 would interfere with federal foreign policy objectives and diplomatic relations, particularly with Mexico.
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Analysis

Foreign Policy Interference

What does this show & who does it help?
This source helps the Federal Government. Immigration involves relationships with other countries — especially Mexico. Only the federal government can handle foreign policy. Arizona's law could damage diplomatic relations and create international problems.
"The Arizona v. United States Immigration Ruling." LegalClarity, legalclarity.org/the-arizona-v-united-states-immigration-ruling/.
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Legal Analysis Federal Gov't

Discrimination and Harassment

The Justice Department presented evidence that SB 1070 could lead to harassment of legal immigrants and U.S. citizens who might be unable to show proof of their immigration status.
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Analysis

Discrimination and Harassment

What does this show & who does it help?
This source helps the Federal Government. The "show me your papers" law could lead to racial profiling. Legal immigrants and U.S. citizens who "look" foreign might be stopped and questioned. This violates equal protection and creates fear in Latino communities.
"The Arizona v. United States Immigration Ruling." LegalClarity, legalclarity.org/the-arizona-v-united-states-immigration-ruling/.
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Legal Analysis Federal Gov't

Frustration of Federal Discretion

The federal government argued that Arizona's statute impermissibly sought to frustrate the discretionary judgments through which the federal government sets immigration policy for the nation.
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Analysis

Frustration of Federal Discretion

What does this show & who does it help?
This source helps the Federal Government. The federal government gets to decide enforcement priorities — maybe focusing on criminals rather than all undocumented people. Arizona's law would force enforcement that the federal government has chosen not to pursue.
"State of Arizona v. United States of America." Federation for American Immigration Reform, www.fairus.org/sites/default/files/2017-08/SB1070_041912.pdf.
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Connecting to Today

How these constitutional questions still matter

The tension between federal and state authority continues to shape American politics. Consider these modern examples:

Immigration

Sanctuary Cities

Some cities refuse to help federal immigration enforcement, calling themselves "sanctuary cities." The federal government argues this interferes with immigration policy.

Think about: If states can't make immigration stricter, can cities make it more lenient?

State vs Federal

Marijuana Legalization

Many states have legalized marijuana, but it remains illegal under federal law. This creates a conflict between state and federal authority similar to the Arizona case.

Think about: When state and federal law conflict, which should win? Does it depend on the issue?

Current Debate

Border Security

States along the border continue to argue they should have more power to enforce immigration laws. Texas has passed its own border security measures in recent years.

Think about: Should states most affected by an issue have more say in how to handle it?

Discussion Questions

  • Why might the Founders have given the federal government power over immigration and foreign relations?
  • What problems could arise if each state had completely different immigration rules?
  • Is there a way for states to address local concerns without conflicting with federal law?

Additional Resources

Go deeper with these resources

📺 Video

Library of Congress Immigration Resources

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📄 Document

US Law Explained - Arizona v. United States

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🎧 Audio

Oyez Audio and Case Summary

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