The U.S. Supreme Court on Monday overturned several parts of Arizona's SB 1070 immigration law, but the justices let stand the provision allowing police to verify the immigration status of people stopped in the normal course of law enforcement.

The 5-3 decision marked a partial political victory for the Obama administration, which challenged the controversial measure on the grounds that Arizona was trying to usurp the federal government's exclusive authority over immigration.

The Supreme Court let stand the article that authorizes police and other agents of law and order to verify the immigration status of people about whom "probable cause" exists to believe they are in the country illegally.

The justices acknowledged, however, that there is "a basic uncertainty about what the law means and how it will be enforced."

"At this stage, without the benefit of a definitive interpretation from state courts, it would be inappropriate to assume (the provision) will be construed in a way that creates a conflict with federal law," Justice Anthony Kennedy said, writing for the majority.

Kennedy and his four colleagues did say the Department of Justice was right to strike down articles 3, 5 and 6 of SB 1070.

One of these provisions criminalized the undocumented for obtaining or simply applying for a job, another authorized the arrest without a warrant of people who have committed a crime that makes them liable for deportation, while the third makes it a state crime if "unauthorized immigrants" fail to register with the federal government.

"Arizona may have understandable frustrations with the problems caused by illegal immigration while that process continues, but the state may not pursue policies that undermine federal law," Kennedy wrote in the 76-page opinion.

All four provisions, including "show me your papers," had been overturned by lower courts.

Arizona Republican Gov. Jan Brewer said in a communique that Monday's ruling was a "victory for the rule of law," and aware of the criticism of SB 1070, pledged to ensure "the implementation and enforcement of this law in an even-handed manner that lives up to our highest ideals as American citizens."

SB 1070 was promoted by groups opposing illegal immigration who argued that the undocumented are a great drain on the public treasury and a risk to national security.

Though it was partially blocked in the courts, its enactment had an undeniable effect in Arizona by striking fear into the immigrant community.

Illegal immigration in Arizona is estimated to have dropped from around 560,000 in 2008 to some 360,000 in January 2011. EFE