"I think that there might be some other cases in which the court will declare some law unconstitutional because it cannot be justified under the commerce clause," Shiffrin said. "But I don't see a sweeping rollback of legislation all the way back to 1937."
The Gun Owners of America and the libertarian Cato Institute cheered the court's decision, the former because it strikes down limits on gun possession and the latter because it narrows Congress' regulatory powers.
The National Education Assn. condemned the ruling for taking away a tool to make schools safer.
The ruling came in a 1992 incident. Alfonso Lopez Jr., then a senior at Edison High School in San Antonio, came to school carrying a .38-caliber handgun and five bullets.
He was arrested and charged under Texas law with firearm possession on school property. The next day, the state charges were dropped and he was rearrested under the federal Gun-Free School Zones Act.
He challenged his conviction on grounds that the federal statute exceeded Congress' authority under the commerce clause. The U.S. 5th Circuit Court of Appeals agreed and overturned his conviction. The Supreme Court agreed.
Also Wednesday, the high court ruled that states may regulate hospital costs by requiring patients covered by employee benefit plans to pay higher rates than those with other types of health coverage (New York State Conference of Blue Cross & Blue Shield Plans vs. The Travelers, 93-1408, 93-1414 and 93-1415).
The unanimous decision reinstated parts of New York's hospital-reimbursement system, saying that it is not preempted by federal law. About half the states have similar provisions, New York officials had told the high court.