The Supreme Court stepped into the fight Monday over a tough Arizona law that requires local police to help enforce federal immigration laws — pushing the court deeper into hot, partisan issues of the 2012 election campaign.

The court's election-year docket now contains three politically charged disputes, including President Barack Obama's health care overhaul and Texas redistricting.

The debate over immigration already is shaping presidential politics, and now the court is undertaking a review of an Arizona law that has spawned a host of copycat state laws targeting illegal immigrants.

The court will review a federal appeals court ruling that blocked several provisions in the Arizona law. One of those requires that police, while enforcing other laws, question a person's immigration status if officers suspect he is in the country illegally.

The case is the court's biggest foray into immigration law in decades, said Temple University law professor Peter Spiro, an expert in that area.