The Supreme Court, in a 5-3 decision, struck down 3 of the 4 provisions in the Arizona immigration law being challenged by the Justice Department. (Justice Kagan recused herself.)

The justices upheld one key provision, but it is unclear whether the law itself will now have to be reworked.

Wall Street Journal:

The Supreme Court upheld a key part of Arizona's tough-immigration law but struck down others as intrusions on federal sovereignty, in a ruling that gave both sides something to cheer in advance of November elections where immigration is a major issue.

The court backed a section of the Arizona state law that calls for police to check the immigration status of people they stop.

That section was one of four at issue before the high court. The others make it a crime for immigrants without work permits to seek employment; make it a crime for immigrants to fail to carry registration documents, and authorize the police to arrest any immigrant they believe has committed a deportable offense. Those other three provisions were struck down.

Five justices were in the majority choosing to strike down the three provisions. Dissenting justices argued that the whole law should have been upheld.

Lower federal courts blocked the four provisions from taking effect after Republican Gov. Jan Brewer signed the measure in 2010. The courts agreed with the Justice Department that the undermined federal authority over immigration.

The law is part of the broader national debate over immigration, which heated up last week when President Barack Obama and Republican rival Mitt Romney spoke before a group of Hispanic officials.

Mr. Obama touted his announcement the previous week that his administration will stop deporting many young illegal immigrants, while Mr. Romney used his speech to soften his tone on immigration and call for a long-term overhaul that would allow more newcomers to receive green cards. The candidates are both stepping up their appeals to the fast-growing bloc of Hispanic voters.

Democrats have accused the Arizona law's supporters of having an anti-immigrant agenda, while the law's mostly Republican backers say they want to secure the nation's borders.

This is not unexpected, as the court rarely upholds states' rights as it relates to issues that are recognized as part of the federal government's mandate to govern. Even if the feds do a lousy job of enforcing immigration law, the states can only go so far when taking matters into their own hands.

Governor Jan Brewer said in her statement that the "heart" of the law was still intact. This is true, but three key enforcement provisions have been struck down, pulling some of the teeth of the law and making it harder for Arizona to stem the flow of illegal immigrants across its borders.