The Texas law that sought to prevent social media platforms such as Facebook and Twitter from censoring users on the basis of their views was blocked by the divided Supreme Court.
Tuesday's unusual 5-4 vote by the court was used to suspend Texas law while a case is pending in lower courts.
Chief Justice John Roberts, Justices Stephen Breyer and Sonia Sotomayor, Brett Kavanaugh, Brett Kavanaugh, Amy Coney Barrett voted in favor of the emergency request by two groups representing the technology industry that challenged the law at federal court.
As is usual in emergency cases on what is informally known as the court’s "shadow docket", the majority did not provide any explanation for their decision.
The law would have been allowed to continue in force if it had been approved by Clarence Thomas, Samuel Alito and Elena Kagan, as well as Neil Gorsuch.
Alito stated in dissent that social media platforms had "transformed the way people communicate with one another and get news."
It is unclear how the Supreme Court's First Amendment cases from the past, many of them predated the internet age. Alito wrote this opinion in a joint opinion with Thomas and Gorsuch, but not Kagan.
This order follows a decision by the 11th U.S. Circuit Court of Appeals ruled that a similar Florida law violates the First Amendment's freedom of speech protections.
Republican elected officials from several states have supported laws such as those in Florida and Texas, which sought to portray social-media companies as liberal and hostile to ideas that are not of their view, especially from the political left.
A Texas district judge blocked the Texas law at first, but then a panel from the New Orleans-based 5th U.S. allowed it to go into effect. Circuit Court of Appeals.
