If the Supreme Court declared that a certain X-rated film was pornographic, would you be more or less inclined to watch it?
The film "Deep Throat" was made on a budget of less than $40,000, yet grossed more than $500 million, primarily because of all the publicity brought about by various Government's censorship and legal actions.
I would think this answers your question, maybe.
In fact, the standard which the United States Supreme Court had established was "community standards." This was from the case in which the Court upheld the conviction in Roth versus the United States in 1957. But subsequent Federal appellate cases, and particular the 1964 Jacobellis versus the State of Ohio, served to show that no standard had in fact been established. In the 1973 case, Miller versus the State of California, the Supremes came up with the "Miller test" to determine obscenity:
* Whether the average person, applying contemporary community standards, would find that the work, taken as a whole, appeals to the prurient interest,
* Whether the work depicts/describes, in a patently offensive way, sexual conduct or excretory functions specifically defined by applicable state law,
* Whether the work, taken as a whole, lacks serious literary and/or artistic, political, or scientific value.
If material alleged to be obscene fails to rise beyond those standards, it can be declared not to be protected by the free speech provision of the First Amendment. The reference to contemporary community standards, however, more or less throws the matter back onto the states, and that means that the states can still legislate and prosecute, but if a conviction is appealed, the state will have to be prepared to show that the material is obscene based on a provision of the Miller test. The net effect has been to loosen restrictions in state laws. In a New York case, the Supremes upheld the idea that child pornography is not protected by the First Amendment, although in a subsequent case, they held that explicit material which only seems to involve minors might be protected--which is par for the course. People often believe that the Supremes have declared this or that to be illegal or legal, and cases at law are far more subtle than that, and certain themes are reviewed again and again; as well, the Supremes often do not clearly define what is or is not permitted by the Constitution.
So, in fact, the Supreme Court is not ever actually telling an American what is or is not pornography. The several States are making that decision, and it often arises that even a lower level of government is making the decision, such as a municipality, as was the case with the photographs of Robert Mapplethorpe in Cincinatti in 1990, when the gallery and its director were unsuccessfully sued for pandering obscenity. Mapplethorpe, himself, however, was beyond the reach of the law, having died of HIV/AIDS in 1989.