Texas passed HB20 last September to combat the allegedly “dangerous movement by social media companies to silence conservative viewpoints and ideas.” Yesterday, in a victory for First Amendment rights on the internet, a sharply divided Supreme Court temporarily blocked the law from going into effect. The Supreme Court is likely to consider this controversial law, or another like it, on the merits in future, and the alignment of votes in yesterday’s decision provides some insight into how the justices would rule in such a case.

HB20 prohibits social media platforms from “censoring” lawful content based on any viewpoint it expresses, ranging from the innocuous—whether pineapple belongs on pizza—to the vile—whether the Holocaust was justified. Platforms that violate this requirement face liability for each piece of content they remove. Any aggrieved user may sue the platforms for “viewpoint discrimination,” even if that user didn’t post the content themselves.

NetChoice and CCIA, two trade associations of online businesses, sued Texas immediately after HB20’s passage in a federal district court, arguing the law violated platforms’ well‐​established First Amendment right to choose what content they host. The district court agreed and issued a preliminary injunction. Texas then appealed the district court’s decision to the Fifth Circuit (where Cato filed a brief in support of NetChoice and CCIA). Though it still has not released an opinion, the Fifth Circuit issued a one-sentence order a few weeks ago, lifting the district court’s injunction and suddenly putting HB20 into effect. NetChoice and CCIA then filed an emergency application to the Supreme Court (where Cato also filed in support of the NetChoice and CCIA) to vacate the stay. A majority of five justices granted the application. HB20 is temporarily blocked once again, pending the Fifth Circuit’s opinion on the merits.

But Justice Alito, writing in dissent for himself and Justices Thomas and Gorsuch, departed from the majority. Those justices believe this case raises “novel” questions concerning “the power of dominant social media corporations to shape public discussion of the important issues of the day.” Alito stressed that he had not formed a definitive view on the merits, but that he would not have stepped in to block the law “at this point in the proceedings.” Justice Kagan, who also dissented from the ruling, did not join Alito’s opinion.

Texas characterizes HB20 as a necessary measure to protect “conservative viewpoints” and “First Amendment rights.” But as we explained in our amicus brief to the Fifth Circuit, the First Amendment protects social media platforms’ right to choose what content they host. It does not empower the government to force private actors to host the content or viewpoints it favors. In fact, the Supreme Court has explicitly protected the First Amendment right to editorial judgment since its 1974 ruling in Miami Herald v. Tornillo. The Court’s ruling in Reno v. ACLU (1997) confirmed that First Amendment rights apply with full force to internet media and, per Brown v. Entertainment Merchants Association (2011), “do not vary when a new medium appears.” The Court has also long held that corporations, like social media platforms, have robust First Amendment rights, perhaps most famously in Citizens United v. FEC (2010). As of yesterday, at least five of the sitting justices presumably acknowledge that precedent is strongly on NetChoice’s and CCIA’s side.

Further, what Texas calls “viewpoint discrimination” is necessary for platforms to serve a broad and diverse group of users, and if the Supreme Court did not vacate the Fifth Circuit’s stay yesterday, Texan users would receive a crash course explaining why. As we argued in our amicus brief to the Supreme Court, HB20’s viewpoint neutrality mandate will flood the websites with all the disturbing yet lawful content that falls within the First Amendment’s broad ambit of protection. This includes terrorist recruitment material, doxxing, and racial epithets because removing this type of content would qualify as viewpoint discrimination.

The prospect of the world’s most popular social media platforms becoming overrun with offensive content under the viewpoint neutrality mandate is not merely speculative. Case studies from unmoderated or lightly moderated platforms—including recent Republican-led attempts to create “free speech” alternatives to Facebook and Twitter—show that proliferation of vile material reliably occurs under a “viewpoint neutrality” moderation rule. This, in turn, always leads to an exodus of many, limiting the exercise of free speech on those platforms to an exceptional few. HB20 aims to combat the purported “discriminatory dystopia” of “anti-conservative censorship,” but prohibiting companies from shielding users from Ku Klux Klan advocacy material is likely not the free speech utopia many users want, regardless of their political affiliation.

Though the Fifth Circuit has not yet released its opinion, its stay of the district court’s preliminary injunction signals that it is likely to uphold the law against the constitutional challenge. This foreshadows an incipient circuit split on whether the First Amendment prohibits the government from forcing social media platforms to host certain content because the Eleventh Circuit recently ruled the opposite way on a similar social media law coming out of Florida. A circuit split on the high-stakes legal question encourages the Supreme Court to weigh and resolve the disagreement.

It is not certain how the justices would rule in such a case, but yesterday’s decision provides some predictive insight. Justice Thomas seems likely to rule against social media platforms because joining Alito’s dissent is the second time he has favored arguments to limit social media platforms’ discretion over what they host. Justice Thomas previously expressed sympathy towards declaring social media platforms “common carriers” in order to limit that discretion in his Biden v. Knight (2021) concurrence.

On the other hand, Justice Kavanaugh seems likely to find in favor of the social media platforms. Joining the majority’s decision yesterday is the second time in recent memory he has opposed impingements on telecommunications’ entities’ autonomy. Then‑D.C. Circuit Court Judge Kavanaugh wrote in his U.S. Telecom v. FEC dissent that the government cannot “tell Twitter or YouTube what videos to post” or “tell Facebook or Google what content to favor.”

Justice Kagan, who also dissented from the majority, did not join Alito’s opinion. Kagan is a known objector to emergency stays, like this one, from the so-called “shadow docket.” Her objection to the application may be procedural, rather than reflective of her opinion of the law on the merits. And though her rationale for denying the application is unclear, it would be surprising if she were to side with the justices most likely to uphold one of these laws, who happen to be among the most conservative.

Alito insists he has not formed a view on the merits, but he wrote that “it is not at all obvious how our existing precedents, which predate the age of the internet, should apply to large social media companies.” His dissent also included a footnote unrelated to the procedural or substantive questions at bar, seemingly to disparage the platforms, by insinuating they are hypocritical in their account of their own activities. This is potentially, though not necessarily, a bad omen for the social media platforms. The other two democrat-appointed justices—Breyer and Sotomayor—are unlikely to find the Republican states’ arguments in favor of forced hosting of conservative speech persuasive. They are likely to rule in NetChoice and CCIA’s favor.

While this is a hot-button issue, it should be a relatively easy case whenever it ultimately reaches the Court. The moderation decisions of a platform are a First Amendment-protected activity. If a new social media platform wanted to advertise itself as allowing racially charged posts, or even hate speech, it would be declaring how it uses its First Amendment-protected right to moderate content. If another platform decides to moderate that content—“you won’t see that stuff here”—then it also has that right.

In that way, social media platforms are not at all like “common carriers,” such as phone companies, which are obliged to accept all users. No one has ever thought that if AT&T lets two Nazis talk on the phone, then Nazism is imputed to the company. For Facebook and other social media companies, however, what content they permit is seen as crucial to the identity of the platform.

As the Eleventh Circuit put it, “when a platform selectively removes what it perceives to be incendiary political rhetoric, pornographic content, or public‐​health misinformation, it conveys a message and thereby engages in ‘speech’ within the meaning of the First Amendment.” In this way, a decision in favor of HB20, or another law like it, runs contrary to the First Amendment and undermines decades of Supreme Court precedent interpreting it. When the Supreme Court considers platforms’ right to moderate content on the merits, it should find in favor of NetChoice and CCIA, like the Eleventh Circuit did, to ensure that well-established civil liberties continue to apply with full force to internet expression.