Washington – The Supreme Court on Monday agreed to decide whether Arizona may impose tough anti-immigration measures. Among them, in a law enacted last year, is a requirement that the police there question people they stop about their immigration status.
The Obama administration challenged parts of the law in court, saying that it could not be reconciled with federal immigration laws and policies. The United States Court of Appeals for the Ninth Circuit, in San Francisco, blocked enforcement of parts of the law in April.
The administration challenged four provisions. The most prominent was a requirement that state law enforcement officials determine the immigration status of anyone they stop or arrest if officials have reason to believe that the individual might be an illegal immigrant. The provision also requires that the immigration status of people who are arrested be determined before they are released.
The law also makes it a crime under state law for aliens to fail to register under a federal one. In a brief urging the Supreme Court not to hear the case, Donald B. Verrilli Jr., the United States solicitor general, said this provision created a state “crime of being unlawfully present in the United States.”
The third challenged provision makes it a crime for illegal immigrants to work or try find work. Federal law subjects businesses that hire illegal workers to criminal punishment but imposes only civil penalties on the workers themselves.
The Arizona law also allows the police to arrest people without warrants if they have probable cause to believe that suspects have done things that would make them deportable under federal law.
The Ninth Circuit blocked all four provisions.
The Constitution gives Congress the power “to establish an uniform rule of naturalization.”
Mr. Verrilli told the justices that the Arizona law upsets a delicate balance that includes “law enforcement priorities, foreign-relations considerations and humanitarian concerns.”
In urging the court to hear the case, Arizona v. United States, No. 11-182, Paul D. Clement, representing Arizona, said the state law did not conflict with but, rather, complemented federal policies. The Ninth Circuit’s decision, Mr. Clement told the justices, had “completely foreclosed Arizona’s effort to address the disproportionate impact of unlawful immigration in a state with a 370-mile border with Mexico.”
Justice Elena Kagan indicated that she would not participate in the case, presumably because she worked on it as solicitor general.
The Supreme Court has recently added other major cases to its docket, including ones concerning President Obama’s health care law and redistricting in Texas. In those cases, too, Mr. Clement, a former United States solicitor general, represents states challenging federal action.