The 11th Amendment to the Constitution, added four years after adoption of the Bill of Rights, says: "The judicial power of the United States shall not be construed to extend to any suit in law or equity, commenced or prosecuted against one of the United States by citizens of another state, or by citizens or subjects of any foreign state."

That gives the states a lot of protection against being hauled into federal court, but not as much as the words might suggest. A new ruling from the U.S. Court of Appeals in Philadelphia made it mean a bit less.

The issue in the newest case, U.S. v. Union Gas, revolves around the power of Congress to regulate interstate business.

In 1976, the U.S. Supreme Court said that the 11th Amendment merely means that private parties cannot sue a state unless Congress has said they can. But that ruling upheld Congressional actions based on the 14th Amendment. Coming more than 70 years later, the 14th Amendment could be read as itself carving out an exception to the 11th.

But what about powers given Congress before the 11th Amendment was added to the Constitution, such as the power to regulate commerce? The high court has never decided whether they, too, can be used to allow private suits against the states.

Last year, the Supreme Court was poised to answer that question, in a dispute over a suit against Pennsylvania for money damages for cleaning up an environmental mess the state is alleged to have caused. The Philadelphia appellate court said that the suit could not be maintained under the existing version of the Superfund Act, because of the 11th Amendment. It just was not clear that Congress had meant to authorize such suits.

But then Congress amended the Superfund Act and left no doubt that it was explicitly authorizing suits against states in just the same way that the statute called for actions against private companies. Given that new language, the high court asked the appellate judges to take another look at the controversy.

Pennsylvania argued that while it is clear what Congress said, the lawmakers -- because of the 11th Amendment -- had no right to say it. The Commerce Clause is limited by the later amendment, the officials insisted.

But on Nov. 3, the judge ruled that the Constitution can't be read on a timeline. The states are still protected by the 11th Amendment because they can't be sued unless Congress says so in the most unequivocal language, they explained. But if one part of the Constitution gives Congress powers that can be used to authorize private suits against the states, then every part of the document must be read that way.

In other cases, courts ruled that:

The U.S. Court of Appeals in Richmond threw out a Virginia tax provision that required companies leasing land or equipment from the federal government to include the value of that property in the tangible personal property taxed by local governments. Lessees of some state property had to pay the tax, too, but not those who used property of the Virginia Port Authority. That was a fatal flaw, the Richmond judges said, because it discriminated against the federal government.

U.S. v. Manassas, Oct. 6

It can be an unreasonable restraint of trade to give some customers discounts or rebates that are not allowed to others.

The Robinson-Patman Act bars such price discrimination among customers, but only if the customers are middlemen competing for the same final customers. The Illinois Appellate Court just two years ago had said that state antitrust laws do not bar such differential pricing, but in its newest decision it reverses that holding. The judges gave the green light to a suit by trustees of union health benefit plans, who objected to the practice at some Chicago hospitals of making rebates to the local Blue Cross plan when charges for Blue Cross patients were more than 5 percent above the hospitals' actual costs of caring for the patients, but refusing to strike such deal with other insurance plans.

Laughlin v. Evanston Hospital, Oct. 21

The Environmental Protection Agency has to be more generous in funding waste treatment plants. When construction plans for such facilities require filling in natural wetlands, environmental regulations often require the sanitation director involved to buy and set aside other wetlands to make up for the loss. EPA refused to use Clean Water Act money for the purchase of such "mitigation wetland." But Chief Judge Lawrence K. Karlton of the U.S. District Court in Sacramento, said that the requirement to add to preserved wetlands made their purchase not a plant site but an integral part of the treatment process, and so must be paid for with federal money.

Sacramento Regional v. Thomas, Oct. 16

The Arkansas Franchise Practices Act, like similar statutes in other states, gives a franchise-holder the right to sue if the franchisor misled him in setting up a "place of business" in the state. But the U.S. Court of Appeals in St. Louis decided that the law does not cover a franchise to sell tools from a mobile van. Bridgeman v. Cornwell, Oct. 19

Moskowitz covers legal affairs for McGraw-Hill World News.