WASHINGTON - The Supreme Court on Thursday upheld an Arizona law that severely penalizes businesses that knowingly hire illegal immigrants.

In a ruling likely to embolden Congress and other states, the court declared that Arizona's law fits comfortably within the state's powers.

"Arizona hopes that its law will result in more effective enforcement of the prohibition on employing unauthorized aliens," Chief Justice John G. Roberts Jr. wrote for the 5-3 majority, adding that "the Arizona regulation does not otherwise conflict with federal law."

The highly anticipated decision keeps intact the 2007 Legal Arizona Workers Act. Under the law, employers' business licenses could be suspended or revoked if they hire illegal immigrants. The ruling will make it easier for states to pass similar laws, even though immigration is traditionally a federal responsibility.

The decision in Chamber of Commerce v. Whiting did not involve a more controversial Arizona measure that requires police to check the immigration status of individuals in certain circumstances. That law remains under separate legal challenge.

The law upheld Thursday also requires Arizona employers to use a federal program called E-Verify to check the immigration status of potential workers. Roberts called this state requirement "entirely consistent" with federal law.

Nationwide, more than 215,000 employers have signed up for the optional E-Verify system. Other states now can follow Arizona's lead to make its use mandatory; South Carolina and Mississippi already have done so. In Congress, some lawmakers soon will introduce legislation that would make E-Verify mandatory everywhere.

"American jobs should be preserved for American workers," said Rep. Lamar Smith (R., Texas), the chairman of the House Judiciary Committee and the author of a pending E-Verify bill.

The decision Thursday affirms the U.S. Circuit Court of Appeals for the Ninth Circuit, which had likewise upheld the state law. It is a defeat for the politically powerful U.S. Chamber of Commerce and the Obama administration, both of which had opposed the law.

"Either directly or through the uncertainty that it creates, the Arizona statute will impose additional burdens upon lawful employers," Justice Stephen G. Breyer wrote in dissent.

Breyer, joined by Justices Ruth Bader Ginsburg and Sonia Sotomayor, added that fearful employers may now "erect ever stronger safeguards against the hiring of unauthorized aliens, without counterbalancing protections against unlawful discrimination."

Justices Antonin Scalia, Anthony M. Kennedy, Samuel A. Alito Jr. and Clarence Thomas joined in most of the majority opinion.

Justice Elena Kagan did not participate in the case because of her prior job as the Obama administration's solicitor general.

Arizona legislators explicitly cited their frustration with the federal gridlock over immigration when they passed the 2007 law. The frustration is widely shared in other states, where legislators introduced more than 1,500 immigration-related bills in 2009, quintuple the number introduced in 2005.

Thirteen states allied themselves with Arizona in citing states' traditional authority over business licensing. These could become the next states to adopt stricter rules.

Cities, too, might seize on the court's ruling. In Pennsylvania, city officials in Hazleton adopted a law similar to Arizona's that prohibits companies from hiring undocumented workers and requires employers to use E-Verify. A federal appeals court struck down Hazleton's law last year; the new ruling might revive it.

In Other Court Action

The Supreme Court

on Thursday overturned

the conviction of a man who killed a police officer in Florida in 1998. The justices said the lower court should reconsider the conviction of Charles Fowler, who was given life in prison. Fowler was convicted under a federal law that bans people from trying to keep U.S. officials from being informed about a potential federal crime. Officer Todd Horner

was killed when he approached a group of men who were planning a bank robbery. Fowler's lawyers said prosecutors never proved Horner would have alerted federal authorities to a potential federal crime. Justices agreed that proof is needed under that law, and sent the case back. The case is Fowler v. United States.

The court threw out

a lower court's ruling that authorities need warrants to talk to potential victims of sex abuse at school, without saying whether it thought the earlier decision was wrong. The high court tossed out the decision by the U.S. Circuit Court of Appeals for the Ninth Circuit in the case of a 9-year-old who was interviewed by a social worker and a police officer at school in Oregon because they suspected that she was being abused by her father. The girl is now nearing her 18th birthday and living in Florida. The challenge to a court ruling that affects children in Oregon is moot because the girl, known in court papers as S.G., would no longer be affected by its outcome, Justice Elena Kagan said. The cases are Camreta v. Green and Alford v. Greene.

The high court said

that the time courts spend dealing with pretrial motions automatically increases the time the government is allowed before bringing a suspect to trial. Despite that, the high court refused to grant the government's request to reinstate Jason Louis Tinklenberg's conviction of gun possession by a felon and possession of material used to manufacture methamphetamine. The Speedy Trial Act says a defendant's trial should begin within 70 days of his indictment or his initial appearance before a judicial officer. The U.S. Circuit Court of Appeals for the Sixth Circuit said the pretrial motion days did count because they did not delay the eventual trial. But the high court ruled that all time used to dispense with pretrial motions do not count toward the Speedy Trial deadline. The case is United States v. Tinklenberg.

- Associated PressEndText

Read the justices' opinions in the Arizona illegal-workers case via http://go.philly.com/arizEndText