From NBC's Pete Williams
Handing a legal victory to groups pushing back against illegal immigration, the Supreme Court today upheld an Arizona law that punishes businesses in the state for hiring workers who are in the country illegally.

Federal law against illegal immigration says the states cannot penalize businesses that hire illegal workers "except through licensing."

So in 2007, Arizona passed a controversial law -- signed by then-Gov. Janet Napolitano  -- that allows the state to take away the business licenses of employers that intentionally hire illegal workers. Led by the US Chamber of Commerce, several business and civil rights groups challenged the law, saying enforcement of the immigation laws is for the federal government.

The Obama administration also sued Arizona over the law. Congress, the groups said, never meant to give the states such latitude over virtually any license to do business.

But today by a 5-3 vote (with Justice Elena Kagan siting this one out), the Supreme Court upheld the Arizona law.

The state is simply imposing the punishments the federal law allows, the court said. In addition, the court pointed out, before a business can lose its license, it must intentionally and repeatedly hire illegal workers.

"Congress did not intend to preserve only state state laws that have no effect" on illegal immigration, said Chief Justice John Roberts, who wrote today's opinion.

Today's ruling is a green light for other states considering laws that punish employers for hiring illegal workers. Nine states have already done so.

The court has yet to take up the far more controversial Arizona law that requires police to round up anyone they think is in the state illegally. And this ruling does not foreshadow how the Supreme Court will rule on that one, because Congress specifically opened the door to the kind of state regulation upheld today.