PHOENIX (CNN) -- The Supreme Court is poised to decide whether Arizona can enforce its controversial immigration law over the strong objections of the Obama administration. Oral arguments will be held Wednesday.
A ruling during a presidential election year could generate renewed political attention on an issue that has been building in intensity in recent years.
Federal courts have blocked four key parts of the state's Support Our Law Enforcement and Safe Neighborhoods Act, known as SB 1070. Arizona has argued that illegal immigration is creating financial hardships and safety concerns for its residents, and that the federal government has long failed to control the problem.
The administration has countered by saying immigration issues are under its exclusive authority and state "interference" would only make matters worse.
The southwest state is the nation's most heavily traveled corridor for illegal immigration and smuggling.
Justice Elena Kagan will not hear this case, because as solicitor general, before taking the bench last year, she had been involved in the administration's initial legal opposition to the law. A 4-4 high court split would be likely to keep the Arizona law in legal limbo, preventing the four provisions of the law from going into effect, but not settling the larger constitutional questions.
It would also shift the election-year fight over the issue to other states with current or pending crackdown laws.
The four Arizona provisions currently on hold are:
-- A requirement that local police officers check a person's immigration status while enforcing other laws, if "reasonable suspicion" exists that the person is in the United States illegally.
-- A provision authorizing police to arrest immigrants without warrant where "probable cause" exists that they committed any public offense making them removable from the country.
-- A section making it a state crime for "unauthorized immigrants" to fail to carry registration papers and other government identification.
-- A ban on those not authorized for employment in the United States to apply, solicit or perform work. That would include immigrants standing in a parking lot who "gesture or nod" their willingness to be employed.
Although the specific question before the high court relates to the law's enforcement, the justices could use the appeal to address the broader constitutional questions. Similar laws are under challenge in lower courts in Georgia, Alabama, Utah and South Carolina. Arizona's appeal is the first to reach the Supreme Court.
Arizona Gov. Jan Brewer said she is confident the high court will rule for the state.
"This case is not just about Arizona. It's about every state grappling with the costs of illegal immigration. And it's about the fundamental principle of federalism, under which these states have a right to defend their people," the Republican governor said in a statement released after the Supreme Court agreed to decide the matter.
"Arizona has been more than patient waiting for Washington to secure the border. Decades of federal inaction and misguided policy have created a dangerous and unacceptable situation and states deserve clarity from the court in terms of what role they have in fighting illegal immigration."
At issue is whether states have any authority to step in to enforce immigration matters or whether that is the exclusive role of the federal government. In dry legal terms, this constitutional question is known as "pre-emption."
Arizona officials will tell the justices they are merely assisting and cooperating with federal authorities, action they say Congress has blessed.
But the administration -- backed by a variety of immigrant and civil rights groups -- says allowing such state authority would hurt relations between the United States and other countries, disrupt existing cooperative efforts and unfairly target legal immigrants.
In a rhetorical rematch of last month's separate arguments over the Obama-backed health care reform law, private attorney Paul Clement will make the case for Arizona while Solicitor General Donald Verrilli will articulate the federal government's position.
The legislation has a variety of supporters and detractors.
Republican lawmakers, outspoken Maricopa County, Arizona, Sheriff Joe Arpaio, and various state governments were among those filing briefs supporting the law. The Mexican government, the Anti-Defamation League, the American Immigration Lawyers Association and the city of Tucson, Arizona, were among those supporting the Justice Department's side.
In its petition to the high court, Arizona says it is the nation's busiest illegal entry point, with many people streaming in from neighboring Mexico.
"Arizona bears the brunt of the problems caused by illegal immigration. It is the gateway for nearly half of the nation's illegal border crossings," said state officials. "Beyond the








