WASHINGTON — The Supreme Court on Tuesday blocked a Texas law that would ban large social media companies from removing posts based on the views they express.
The court’s brief order was unsigned and gave no reasons, which is typical when the justices act on emergency applications. The order was not the last word in the case, which is pending before a federal appeals court and may return to the Supreme Court.
The vote was 5 to 4, with an unusual coalition in dissent. The court’s three most conservative members — Justices Samuel A. Alito Jr., Clarence Thomas and Neil M. Gorsuch — filed a dissent saying they would have let stand, for now at least, an appeals court order that left the law in place while the case moved forward. Justice Elena Kagan, a liberal, also said she would have let the order stand, though she did not join the dissent and gave no reasons of her own.
Justice Alito wrote that the issues were so novel and significant that the Supreme Court would have to consider them at some point.
“This application concerns issues of great importance that will plainly merit this court’s review,” he wrote. “Social media platforms have transformed the way people communicate with each other and obtain news. At issue is a groundbreaking Texas law that addresses the power of dominant social media corporations to shape public discussion of the important issues of the day.”
Justice Alito said he was skeptical of the argument that the social media companies have editorial discretion protected by the First Amendment like that enjoyed by newspapers and other traditional publishers.
“It is not at all obvious,” he wrote, “how our existing precedents, which predate the age of the internet, should apply to large social media companies.”
The law’s supporters said the measure was an attempt to combat what they called Silicon Valley censorship, saying major platforms had removed posts expressing conservative views. The law was prompted in part by the decisions of some platforms to bar President Donald J. Trump after the Jan. 6, 2021, attack on the Capitol.
The law, H.B. 20, applies to social media platforms with more than 50 million active monthly users, including Facebook, Twitter and YouTube. It does not appear to reach smaller platforms that appeal to conservatives, like Truth Social and Gettr, the law’s challengers told the Supreme Court.
The law also does not cover sites that are devoted to news, sports, entertainment and other information that their users do not primarily generate. The covered sites are largely prohibited from removing posts based on the viewpoints they express, with exceptions for the sexual exploitation of children, incitement of criminal activity and some threats of violence.
According to two trade groups that challenged the law, the measure “would compel platforms to disseminate all sorts of objectionable viewpoints — such as Russia’s propaganda claiming that its invasion of Ukraine is justified, ISIS propaganda claiming that extremism is warranted, neo-Nazi or K.K.K. screeds denying or supporting the Holocaust, and encouraging children to engage in risky or unhealthy behavior like eating disorders.”
The law requires platforms to be treated as common carriers that must convey essentially all of their users’ messages rather than as publishers with editorial discretion.
In a separate case last week, the U.S. Court of Appeals for the 11th Circuit largely upheld a preliminary injunction against a similar Florida law.
“Social media platforms exercise editorial judgment that is inherently expressive,” Judge Kevin C. Newsom wrote for the panel. “When platforms choose to remove users or posts, deprioritize content in viewers’ feeds or search results, or sanction breaches of their community standards, they engage in First Amendment-protected activity.
The First Amendment generally prohibits government restrictions on speech based on content and viewpoint. In their emergency application to the Supreme Court, the trade groups challenging the Texas law said it ran afoul of those principles at every turn. “H.B. 20 is a flatly unconstitutional law that compels government-preferred speech from select private entities and would require enormous upheaval to the worldwide operations of covered internet websites,” the application said.
In response to the emergency application, Ken Paxton, Texas’ attorney general, wrote that “the platforms are the 21st-century descendants of telegraph and telephone companies: that is, traditional common carriers.” That means, Mr. Paxton wrote, that they must generally accept all customers.
Judge Robert Pitman of the Federal District Court in Austin issued a preliminary injunction blocking the law in December. “Social media companies have a First Amendment right to moderate content disseminated on their platforms,” wrote Judge Pitman, who was appointed by President Barack Obama.
The state’s appeal was argued on May 9 in the U.S. Court of Appeals for the Fifth Circuit. Two days later, a divided three-judge panel of the court stayed Judge Pitman’s injunction and allowed the law to go into effect. The panel has not yet issued a ruling on the merits of the appeal.
The members of the panel — Judge Edith H. Jones, who was appointed by President Ronald Reagan; Judge Leslie H. Southwick, who was appointed by President George W. Bush; and Judge Andrew S. Oldham, who was appointed by Mr. Trump — gave no reasons for their votes, saying only that “the panel is not unanimous.”
The trade groups challenging the Texas law — NetChoice and the Computer & Communications Industry Association — are represented by prominent conservative lawyers, including Scott A. Keller and Kyle Hawkins, who served as solicitors general of Texas, and Paul D. Clement, who served as U.S. solicitor general in Mr. Bush’s administration. In their emergency application to the Supreme Court, they wrote that social media companies’ content moderation policies were crucial to their identities and missions.
“Without these policies,” they wrote, “these websites would become barnacled with slurs, pornography, spam and material harmful to children.”
