The US Supreme Court appeared to lean Wednesday in favor of upholding a controversial Arizona immigration law, brushing back arguments that the southwestern state's crackdown on illegal immigrants encroaches on federal powers.
More than 1,000 protesters outside the court lashed out against provisions of the law that they say encourages ethnic profiling as the justices heard arguments for and against the 2010 law, known as SB1070.
It was the second time this session that the top US court has waded into a hot-button election year issue, after holding three days of hearings last month on President Barack Obama's landmark health care reform laws.
The Arizona law has aroused intense controversy because of provisions that require police to stop and demand proof of citizenship of anyone they suspect of being illegal, even without probable cause.
But Chief Justice John Roberts immediately put Solicitor General Donald Verrilli on the spot by pointing out that the federal government's arguments could not center on the civil rights issues, but rather on its claim under the constitution to exclusive authority in immigration matters.
"No part of your argument has to do with racial or ethnic profiling?" Roberts asked.
Verrilli agreed, saying: "The Constitution vests exclusive authority over immigration matters with the national government."
Roberts however went on to suggest that the law's most controversial provisions were not an effort to override federal law, but to support it.
Justice Anthony Kennedy, often the swing vote on the court, said Arizona was "cooperating in implementing federal law."
The court's conservative majority has been strengthened in this case because Justice Elena Kagan, who served as solicitor general under Obama, recused herself, leaving only eight justices to hear the matter.
But even the three more liberal justices showed little enthusiasm for the government's position, although Justice Stephen Breyer expressed concern that the Arizona law would lead to longer detentions of significant numbers of people.
Paul Clement, who argued Arizona's case, hammered away at the position that the state's law was compatible with federal law, insisting "there is no interference with federal authority."
Outside the court, more than 1,000 opponents of the law gathered to denounce it as a violation of civil rights and a vehicle for discrimination against Hispanics.
"God, give us the courage to stand up against Draconian immigration laws," Reverend Gabriel Salguero, president of the National Latino Evangelical Coalition, said in a prayer.
But conservative backers of the law emerged from the hour-long oral arguments optimistic that their side would prevail in June, when the court is expected to hand down its decision in the thick of the election campaign.
"I was very gratified. I thought they had a handle (on the issues) and I thought it was a clear victory," Russell Pearce, the Arizona state senator who wrote the law, told reporters.
Last year, lower courts opted to strike sections of the law they said would place a burden on legal resident aliens in Arizona, where a third of the 6.6 million people are foreign-born and more than 400,000 are illegal immigrants.
But Arizona appealed, claiming that "the federal government has largely ignored Arizona's pleas for additional resources and help" in stemming the tide of illegal immigration into the state, which borders Mexico.
Arizona governor Jan Brewer -- who earlier this year was caught on camera pointing her finger in Obama's face in what looked to be a testy exchange on an airport tarmac -- has asked the top court to reinstate the suspended sections.
Beyond the identity checks without probable cause, the other sections in question would make it a crime to be in the United States unlawfully and require non-citizens to carry their identity papers with them at all times.
Also at issue is a provision that would make it a crime for illegal migrants to seek work, and one authorizing law enforcement officials to stop anyone they believe may have committed a crime that would result in their expulsion.
If there is a four-four tie, the lower court's decision to strike the provisions will be upheld.
"This case has huge implications for law enforcement and for civil rights. If the Supreme Court decides the wrong way, it's going to be a battle all over the country, state after state," said Anthony Romero, director of the American Civil Liberties Union.
Mexico and 17 other countries have also filed arguments with the Supreme Court opposing the law, saying the delegation of authority over such matters to individual states threatens bilateral relations with Washington.
Verrilli pointed out that the case could have significant consequences for Washington's relations with other countries, to which Justice Antonin Scalia replied: "We have to enforce our laws in the manner that pleases Mexico?"
At least 36 states have introduced legislation with elements similar to those in Arizona, five of which have been passed.