WASHINGTON -- The Supreme Court added another election-year blockbuster to its docket Monday, as the justices agreed to review Arizona's most controversial immigration law.

Amid lots of sideline kibitzing, justices said they'd review whether Arizona legislators went too far when they added immigration enforcement to local law enforcement duties.

The court's decision means that the justices will be front and center on at least two politically incendiary issues just as the presidential and congressional campaigns are heating up.

The court had agreed previously to hear challenges to the Obama administration's health care law.

Now "add to that a major immigration decision that implicates the federal-state balance of power, and you've got one of the most momentous terms in recent court history," said Elizabeth Wydra, chief counsel of the Constitutional Accountability Center, a progressive advocacy group.

The Arizona law requires that officers make a "reasonable attempt" to check the immigration status of individuals whom they've stopped and for whom they have "reasonable suspicion" of being in the United States illegally. The law also requires that officers check the immigration status of anyone they arrest before the individual is released.

The chief legal question is whether Arizona's 2010 law infringes on the federal responsibility for handling border security and immigration.

"Arizona was acutely aware of the need to respect federal authority over immigration-related matters," attorney Paul Clement said in an Arizona legal brief, further describing the state law as "cooperative" with federal efforts.