Updated

The U.S. Supreme Court is set to decide the fate of Arizona's tough anti-immigration law this week, in a ruling likely to affect the national debate over immigration ahead of the November elections.

The court could strike down the challenged provisions as an intrusion on federal sovereignty, uphold them as a legitimate public-security effort by the state, or take a piece-by-piece approach that could leave both sides claiming victory. Some justices at arguments in April suggested they weren't troubled by a section of the Arizona law directing police officers 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.

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

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

Obama touted his announcement the previous week that his administration will stop deporting many young illegal immigrants, while 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.

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