Advertising industry officials said last week that a Supreme Court decision July 1 upholding Puerto Rico's ban on advertising casino gambling to the island's residents does not fundamentally change the rules that have helped the tobacco and alcohol industries fend off bans on advertising.

Attempts to ban advertising of those products would fail the tests that still survive in the law and would be ruled unconstitutional, they argue.

Even so, they said, the ruling could encourage further efforts to restrict advertising of products that have come under fire because of their impact on users' health.

"There are too many products that some groups just don't like, and, instead of attacking the product, because that would be fruitless, they'll attack the advertising," said John E. O'Toole of the American Association of Advertising Agencies.

"If you get into food products that people don't like, potato chips might be next. Who knows? Automobiles cause more deaths than cigarettes," said O'Toole, former chairman of the board of Foote, Cone & Belding. "Anything is possible once the first advertising ban is upheld. And, although it was cloudy and was 5-to-4, that was what the Posadas case was."

To the proponents of a ban on the advertising and promotion of tobacco products, it isn't cloudy at all. In their view, they have been armed with a strong, new weapon.

The Supreme Court, they said, has knocked the props out from under one of the tobacco and advertising industries' most persuasive arguments against an advertising ban: that such a prohibition would be an unconstitutional infringement on free speech.

"The United States Supreme Court has just rendered an opinion that removes any legitimate doubts as to the constitutionality of an advertising ban," Dr. Ronald M. Davis, a member of the board of trustees of the American Medical Association, said last week at a House subcommittee hearing. Davis testified in support of a bill introduced by Rep. Mike Synar (D-Okla.) that would ban tobacco-products advertising and promotion.

The advertising and promotion for tobacco products account for more than $2 billion in spending each year and provide substantial revenue for major newspapers and magazines. They also account for about half of billboard advertising in the United States.

The court held that Puerto Rico did not violate the Constitution's First Amendment by banning casino-gambling advertising "addressed" to the island's residents while permitting other advertising. A hotel in Puerto Rico that was fined $2,000 for violating the restriction sued, claiming that its First Amendment rights were violated.

"We have no difficulty in concluding that the Puerto Rico legislature's interest in the health, safety and welfare of its citizens constitutes a 'substantial' government interest" that outweighed the First Amendment rights of the casino owners, the court said.

"Advertisers will no longer be able to hide behind the First Amendment," said Bruce Silverglade of the Center for the Science in the Public Interest, a group that has challenged advertising by alcohol-beverage manufacturers, fast-food purveyors and others.

"Proponents of the ban argue that the Posadas case gives them support. Our response is, it doesn't change the law, and the government can't ignore the fact that bans don't work," said Wally Snyder of the American Advertising Federation.

What Snyder and others argue is that the court ruling leaves intact tests for constitutionality that were set up in a 1980 Supreme Court ruling in the case of Central Hudson Gas and Electric Corp. v. Public Service Commission of New York. One of those tests would require that a ban further a "substantial interest" of society and be a less restrictive method of doing so than other available methods.

What the Posadas case appears to have done is to shift the arguments about the proposed tobacco products advertising and promotion ban from more general arguments on freedom of speech to specific arguments on whether bans in other countries have worked. If they haven't worked, opponents argue, they cannot meet the test of upholding the "public interest" in reducing consumption.

The advertising and tobacco industries argue they have not. "In Europe and elsewhere, bans on tobacco have been imposed, and, instead of limiting consumption, consumption has gone up," said Dan Jaffe of the National Association of Advertisers. "For instance, in Italy, it has doubled. If you look at the data, and the data says consumption has not been lowered, you cannot logically maintain that the regulations are going to directly further the substantial state interest which is to protect the public health."

Proponents of advertising bans argue that they have worked in countries where the bans have not been riddled with loopholes and where they have been bolstered by public education and effective implementation.

Thomas McGrew, an attorney who specializes in advertising law, said that an interesting facet of the recent court decision is that, on the basis of little evidence about whether the restrictions in question met the existing legal tests, the court gave "the benefit of the doubt to the legislature."

What happens now depends on how other cases go, he said. "The scenario works this way: That case brings the would-be advertising censors out of the woodwork. The first case would be the ones where they think they can get the most support for a ban, such as alcohol and cigarettes."

But if other bans are upheld, advertising restrictions that once existed for groups such as doctors and morticians might be reimposed, he said. Those restrictions were often supported by the restricted groups, which argued that they were helpful in upholding professionalism by preventing cut-rate services. Consumers argued against them, saying that they kept prices artificially high.

The industries are supported by some civil libertarians and First Amendment specialists. "Well-meaning folks are forever offering to improve on the First Amendment by suppressing speech that they deem harmful or offensive," Burt Neuborne, legal director of the American Civil Liberties Union, wrote last week in an article that appeared on The Washington Post's op-ed page.

Scott Stapf, assistant to the president of the Tobacco Institute, said: "I think it will be a cold day in hell before Congress goes ahead with a total ban on advertising of a legal product."