The Supreme Court has voted 5-4 to block Texas' social media censorship law, a major boon for tech companies who have been fighting against content moderation laws that would fundamentally change how they do business.

Why it matters: Conservative states have launched a legal war on social media companies in an effort to stem what they see as a wave of censorship, but this decision, like other recent rulings, suggests they face an uphill climb in court.

What's happening: The Supreme Court's decision means that Texas can't enforce a new law that would allow Texans and the state's attorney general to sue tech giants like Meta and YouTube over their content moderation policies.

• The court's order isn't a final ruling on the merits of Texas' law, but when the courts freeze a particular law or policy, it's often a sign the measure faces a difficult road on the merits.
• It comes just a few days after a federal appeals court ruled against a similar law in Florida.

Catch up quick: Texas passed its law last September, and opponents immediately challenged it in federal court, winning an injunction suspending it from going into effect.

• But earlier this month, the Fifth Circuit Court of Appeals ruled the law could go into effect immediately.
• Opponents appealed that ruling to the Supreme Court and won.

Details: Justices Amy Coney Barrett, Stephen Breyer, Sonia Sotomayor, Brett Kavanaugh and Chief Justice John Roberts voted to reinstate the lower court's injunction and block the law from taking effect.

• Justices Neil Gorsuch, Elena Kagan, Samuel Alito and Clarence Thomas voted against doing so.
• Alito wrote a dissent, arguing, "It is not at all obvious how our existing precedents, which predate the age of the internet, should apply to large social media companies."

What's next: The case returns to district court, where arguments on both sides will be made on the merits.