The Obama administration is asking the Supreme Court to overturn an appeals court decision that upheld Arizona's right to punish employers for hiring illegal immigrants.
The Arizona law gives the state the right to suspend or terminate business licenses.
"If you hire a person in this country illegally knowingly, you'll lose your license. First offense, 10 days. Second offense, revocation, never to do business in the state of Arizona again," said Arizona state Sen. Russell Pearce, a Republican who helped draft the new controversial Arizona law that cracks down on illegal immigrants.
The Obama administration apparently worries letting that law stand would leave in place a precedent that states have a legitimate role in enforcing immigration laws – a notion the administration fiercely opposes.
"The argument that the Justice Department is making here, is you know, the fundamental question, which is where does state authority begin and end when it comes to federal immigration law?" said Benjamin Johnson, executive director of the American Immigration Council.
The Arizona statue relies on a law passed by the U.S. Congress in 1986, which made clear federal law preempts the states on immigration – but left one exception: "The provisions of this section preempt any state or local law imposing civil or criminal sanctions (other than through licensing and similar laws) upon those who employ unauthorized aliens."
"Congress said very clearly that licensing and similar laws can be used to impose consequences on employers who hire unauthorized aliens at the state level," said Kris Kobach, a law professor at the University of Missouri, Kansas City. "And that's exactly what Arizona did."
Oddly enough, the law in question was signed in 2007 by then-Gov. Janet Napolitano, now Obama's Homeland Security secretary.
Not only that, but the law was upheld by the 9th Circuit Court of Appeals in San Francisco.
"And bear in mind that 9th Circuit is generally regarded as one of the more liberal circuits in the United States – and so the Obama administration, evidently, believes that the 9th Circuit views on this question is too conservative for this administration," Kobach said.
And this is yet another issue in the ongoing tug of war between Washington and the states, especially Arizona.
"The idea that states can't be involved in immigration law in any way is wrong," Johnson said. "The states have always had a role to play in immigration enforcement. The tricky part is defining where that authority begins and ends."