WASHINGTON -- The Supreme Court said Monday that the federal government has the sole power to enforce the laws against illegal immigration, striking down three key provisions of Arizona’s first-in-the nation crackdown on undocumented residents.

“Arizona may have understandable frustrations with the problems caused by illegal immigration,” said Justice Anthony M. Kennedy, writing for the majority, “but the state may not pursue policies that undermine federal law.”

But the 5-3 decision was not a total loss for Arizona. The justices cleared the way for state officials to begin enforcing a provision that calls on police, when making lawful stops, to check the immigration status of people who may be in the country illegally. These status checks should not “result in prolonged detention,” Kennedy said.

The decision may be a partial, symbolic victory for Arizona Gov. Jan Brewer, but it is a much bigger win for President Obama. His administration had sued to block the Arizona law from taking effect, and it prevailed on three of the four provisions under dispute.


The high court struck down parts of Arizona’s SB 1070 that made it a state crime for illegal immigrants to seek work and to not to carry immigration papers. The justices also blocked a provision that gave the police authority to arrest immigrants for crimes that may lead to deportation.

“Federal law makes a single sovereign responsible for maintaining a comprehensive and unified system to keep track of aliens within the nation’s borders,” Kennedy wrote. If Arizona could arrest and hold immigrants for not carrying papers, “every state could give itself independent authority to prosecute federal registration violations.”

Chief Justice John G. Roberts Jr. and Justices Ruth Bader Ginsburg, Stephen G. Breyer, and Sonia Sotomayor joined with Kennedy in an opinion that appears to give states little new authority to enforce immigration law on their own.

Justices Antonin Scalia, Clarence Thomas and Samuel A. Alito Jr. each filed dissents. Scalia went the furthest: “As a sovereign, Arizona has the inherent power to exclude persons from its territory.”


Arizona adopted its strict law targeting illegal immigrants in 2010; since then, five other states -- Alabama, Georgia, South Carolina, Indiana and Utah -- have adopted similar measures.

The Obama administration went to court and argued these state laws conflicted with the federal government’s power to enforce the nation’s immigration laws. A federal judge in Phoenix and the U.S. 9th Circuit Court of Appeals had blocked four key parts of Arizona’s law from going into effect.

Monday’s ruling in Arizona vs. United States keeps three of those provisions on hold, but allows the state to begin enforcing the provision that says the police who lawfully stop persons should check their immigration status if there is reason to believe they are in the country illegally.

david.savage@latimes.com