A clash over immigration law will go before the U.S. Supreme Court this week, pitting the state of Arizona against President Barack Obama in a case with election-year political ramifications for him and Republican rival Mitt Romney.
In its second-biggest case this term, the court - fresh from hearing the Obama healthcare overhaul case - will consider on Wednesday whether a tough Arizona immigration crackdown strayed too far into the federal government's powers.
A pro-Arizona decision would be a legal and political setback for Obama, who has criticized the state's law and vowed to push for immigration legislation if re-elected on November 6.
A decision against Arizona would deal a blow to Romney, who has said the government should drop its challenge to the law.
Americans generally support immigration laws like Arizona's and are ambivalent about the federal and state roles at the core of the case, a new Reuters/Ipsos opinion poll found.
About 70 percent of those surveyed favored state laws that let police check a person's immigration status and make it a crime for an illegal immigrant to work in the United States; about 30 percent opposed such measures.
On the question of who has responsibility for immigration laws, the core of the Supreme Court case, 59 percent said immigration was a national issue and laws relating to it should only be made by the federal government; 55 percent said individual states had the right to make such laws, too.
The oral arguments on this essential point set the stage for a rematch of the attorneys in last month's healthcare battle.
Paul Clement, a solicitor general during Republican George W. Bush's presidency, will represent Arizona.
Donald Verrilli, a former White House lawyer and solicitor general under Obama, will represent the federal government after what some deemed a lackluster performance in March.
The case "pits a politically conservative state against a Democratic administration ... just six months before the presidential-year elections," said Steven Schwinn, a John Marshall Law School professor.
Like the healthcare case, the immigration case splits along party lines. Some Republican-led states and Romney supported Arizona's effort to push out illegal immigrants, while some Democratic-led states backed the federal government and Obama.
Legal and political experts said the Supreme Court's rulings, expected by June on immigration and healthcare - two hot-button issues - will weigh heavily on the elections.