WASHINGTON (AP) -- The Supreme Court will referee another major clash between the Obama administration and the states, this one over Arizona's crackdown on illegal immigrants. The case could add fuel to the partisan split over tough state immigration laws backed by Republicans but challenged by the administration.
Like last month's arguments over President Barack Obama's health care overhaul, the immigration case is expected to be decided at the end of June.
Wednesday's arguments will focus on whether states can adopt their own immigration measures to deal with an estimated 11 million illegal immigrants, or whether the federal government has almost exclusive authority in the area of immigration.
Arizona was the first of a half-dozen states to enact laws intended to drive illegal immigrants elsewhere, a policy known as "attrition by enforcement." Even where blocked by courts, these laws have already had an impact on farm fields and school classrooms as fewer immigrants showed up.
"If the federal government had been doing and would continue to do its job in securing the border here in southern Arizona, this would not be an issue. Unfortunately, they failed to do that so Arizona stepped up and said, 'We want to be partners. Here's a role we think we can play,'" said Sheriff Larry Dever of Cochise County, which shares an 83.5-mile border with Mexico in the state's southeastern corner.
The administration says it has both increased border enforcement to keep people from entering illegally in the first place and picked up the pace of deportations. In its first two years, the administration deported nearly 800,000 people, far higher on a yearly basis than President George W. Bush's administration.
The Obama administration sued to block the Arizona law soon after its enactment two years ago. Federal courts have refused to let four key provisions take effect: requiring police, while enforcing other laws, to question a person's immigration status if officers suspect he is in the country illegally; requiring all immigrants to obtain or carry immigration registration papers; making it a state criminal offense for an illegal immigrant to seek work or hold a job and allowing police to arrest suspected illegal immigrants without warrants.
Five states -- Alabama, Georgia, Indiana, South Carolina and Utah -- have adopted variations on Arizona's law. Parts of those laws also are on hold pending the outcome of the Supreme Court case.
Civil rights groups that mounted legal challenges independent of the administration's say the laws encourage racial profiling and ethnic stereotyping. "It blurs what used to be a very bright line, that you can't stop someone and ask for papers based just on how they look," said Anthony Romero, executive director of the American Civil Liberties Union. "But the impact is on citizens as much as immigrants. It's a dragnet approach that sweeps up law-abiding American citizens based on the color of their skin or ethnic origins."
And the state laws already have had a marked effect on people's behavior, whether or not the laws ever went into force, the groups say.
In some states, crops rotted in fields for want of workers to pick them. In Alabama, where a provision required schools to check student's citizenship status, more than 2,000 students stayed home the first week the law was in effect, said Karen Tumlin, managing attorney for the National Immigration Law Center. Foreign employees, including a German Mercedes-Benz executive, have been detained or ticketed for not carrying immigration documents.
In Arizona, around the time Gov. Jan Brewer signed the immigration law, lifelong Arizona resident Jim Shee twice confronted police officers who came to his car window asking to see his "papers."
Shee, 72, is of Chinese and Spanish descent. "I'm not blond-haired and blue-eyed. My grandkids aren't blond-haired and blue-eyed. I don't want to see this happening to them," Shee said.
He has joined a lawsuit filed by a coalition of civil rights groups. The suit is on hold until the high court renders a decision.
Shee said he carries his passport in case he gets stopped again.
The number of illegal immigrants in Arizona has declined by about a third in recent years, from 530,000 in 2007 to 360,000 in 2011, according to federal government estimates.
Experts have attributed the decrease to several factors, including the economic downturn, tighter border security and state immigration laws. A 2007 Arizona law, allowed to take effect last year by the Supreme Court, prohibits employers from knowingly hiring illegal immigrants.
But in Arizona and elsewhere, the appetite for new immigration measures appears to have waned, in part because business leaders have objected. Arizona voters ousted Republican state Sen. Russell Pearce, the architect of the 2010 law and the driving force behind other Arizona immigration laws, in a November recall election.
"There has been a great deal of buyer's remorse in those states that have enacted Arizona-type legislation," the ACLU's Romero said.
The high court decision will land in the middle of a presidential campaign in which Obama has been heavily courting Latino voters and presumptive Republican nominee Mitt Romney has been struggling to win Latino support after a drawn-out primary campaign in which he and the other GOP candidates mostly embraced a hard line to avoid accusations that they support any kind of "amnesty" for illegal immigrants living in the U.S.
Justice Elena Kagan sat out last year's case and also will not take part in the new immigration case, presumably because of her work in the Obama administration. The court's conservative majority held sway in last year's 5-3 decision.
Associated Press writer Jacques Billeaud in Phoenix contributed to this story.