WASHINGTON — The U.S. Supreme Court brushed aside free-speech concerns on Monday as it upheld a law that made it a crime to promote child pornography.

In the 7-2 decision, the court said that the 2003 law setting a five-year mandatory prison term for promoting, or pandering, child porn fails to cast so wide a net that it would ensnare the makers of mainstream movies, TV shows or literature that depict teenage sex or grandparents who send e-mails that describe pictures of grandchildren.

The ruling upheld part of the 2003 Prosecutorial Remedies and Other Tools to End the Exploitation of Children Today (PROTECT) Act that also prohibits possession of child porn. It replaced an earlier law against child pornography that the court struck down as unconstitutional.

The law does not require that someone actually possess child pornography, merely that they were seeking to obtain or distribute it.

Opponents of the law fear that it could apply to movies like “Traffic” or “Titanic” that depict adolescent sex.

In his opinion for the court, Justice Antonin Scalia, rejected those arguments.

“(The PROTECT Act’s) requirement of a ‘visual depiction of an actual minor’ makes clear that, although the sexual intercourse may be simulated, it must involve actual children (unless it is obscene),” he wrote. “This change eliminates any possibility that virtual child pornography or sex between youthful-looking adult actors might be covered by the term ‘simulated sexual intercourse.’ ”

First Amendment protections do not apply to “offers to provide or requests to obtain child pornography,” he wrote.

Justice David Souter, joined by Justice Ruth Bader Ginsburg, dissented. Souter said promotion of images that are not real children engaging in pornography still could be the basis for prosecution under the law. Possession of those images, on the other hand, may not be prosecuted, Souter said.

“I believe that maintaining the First Amendment protection of expression we have previously held to cover fake child pornography requires a limit to the law’s criminalization of pandering proposals,” Souter said.