By Jerry Markon
Washington Post Staff Writer
Monday, November 1, 2010; 6:27 PM

A federal appellate judge expressed deep skepticism Monday about a Justice Department lawsuit challenging Arizona's new immigration law, leaving uncertain the Obama administration's chances of stopping the law from taking effect.

Judge John T. Noonan Jr. grilled administration lawyers at a hearing before the U.S. Court of Appeals for the 9th Circuit. He took aim at the core of the Justice Department's argument: that the Arizona statute is "preempted" by federal law and is especially troublesome because it requires mandatory immigration status checks in certain circumstances.

"I've read your brief, I've read the District Court opinion, I've heard your interchange with my two colleagues, and I don't understand your argument," Noonan told deputy solicitor general Edwin S. Kneedler. "We are dependent as a court on counsel being responsive. . . . You keep saying the problem is that a state officer is told to do something. That's not a matter of preemption. . . . I would think the proper thing to do is to concede that this is a point where you don't have an argument."

"With respect, I do believe we have an argument," said Kneedler, who asserts that the Arizona law is unconstitutional and threatens civil liberties by subjecting lawful immigrants to "interrogation and police surveillance.''

The exchange came at a hearing on efforts by the Justice Department to overturn the Arizona law, which empowers police to question people they suspect are in the country illegally and has triggered a fierce national debate. A federal judge in Phoenix issued a July injunction blocking the law's most contested provisions from taking effect. Arizona appealed, leading to the Monday hearing.

With Noonan, an appointee of President Ronald Reagan, so bluntly stating his views, legal experts said the government's chances of having the injunction upheld may rest with the other two judges on Monday's panel: Carlos T. Bea and Richard A. Paez.

Bea is also a Republican appointee and tends to vote with the court's conservative wing, which could help Arizona's chances. Paez is a Democratic appointee.

But Bea and Paez are Hispanic, and it is Hispanics who are most upset about the Arizona law. "Perhaps this is one area where Bea might not vote as a so-called conservative because he himself is an immigrant,'' said Arthur Hellman, a University of Pittsburgh law professor and an expert on the 9th Circuit.

Bea did not make his position clear during Monday's argument, but he sharply questioned Arizona's attorneys. "Your argument that a state can take a look at whether the federal government is not enforcing its laws. . . . You can enforce laws for the federal government?" he asked. "If I don't pay my (federal) income taxes, can California sue me?''

Whatever the result, the panel's decision is the first step on a long road: legal experts expect the case to reach the Supreme Court. It is unclear when the panel will rule.

The Justice Department lawsuit, filed in July, triggered opposition from Republicans but praise from civil rights groups.

U.S. District Judge Susan R. Bolton in July put on hold provisions of the law that would require police to check immigration status if they stop someone while enforcing other laws, allow for warrantless arrests of suspected illegal immigrants and criminalize the failure of legal immigrants to carry their documentation.

Kneedler, a widely respected appellate lawyer, urged the judges to uphold the injunction while the federal lawsuit proceeds. "This is an extraordinary state statute," he told the judges, saying that provisions such as the criminalization of failure to carry registration papers "are clearly preempted . . . it's a direct regulation of immigration."

Arizona's lawyer, John J. Bouma, defended the law's constitutionality and said Arizona passed it because of "a federal government that has been unable or unwilling to solve" the illegal immigration problem.

Civil rights groups have said the law targets Hispanics, but Bouma, a leading Phoenix lawyer, objected to that characterization. "Arizona has a long and proud tradition of a Hispanic population, and nobody is trying to take away from that,'' he said.

Staff researcher Julie Tate contributed to this report.