Originally Published: 18 MAY 22 16:56 ET

Updated: 19 MAY 22 08:13 ET

By Brian Fung and Ariane de Vogue, CNN

(CNN) -- The Supreme Court should allow a sweeping Texas law to remain in effect that restricts the ability of Facebook, Twitter and YouTube to moderate their platforms, according to the state's attorney general.

In a filing to the Court on Wednesday, Texas argued that its law, HB 20, which prohibits large social media firms from blocking, banning or demoting posts or accounts, does not violate the First Amendment.

It contrasts with claims by opponents, including the tech industry, that the legislation infringes on the constitutional rights of tech platforms to make editorial decisions and to be free from government-compelled speech.

The case is viewed as a bellwether for social media and could determine whether tech platforms may have to scale back their content moderation and allow a broad range of material that their terms currently prohibit.

A group of states led by Florida has also submitted a Court filing defending Texas's law. The friend-of-the-court brief, which was authored by a dozen states including Alabama, Arizona, Kentucky and South Carolina, among others, reflects how the legal battle over HB 20 has nationwide ramifications.

Justice Samuel Alito is currently considering whether to grant an emergency stay of a lower court decision that had allowed the law to take effect last week. The law is being challenged by advocacy groups representing the tech industry.

In court papers, the advocacy groups call the law "an unprecedented assault on the editorial discretion of private websites." They warn it 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 KKK screeds denying or supporting the Holocaust, and encouraging children to engage in risky or unhealthy behavior like eating disorders."

In response on Wednesday, Texas Attorney General Ken Paxton argued that HB 20 does not infringe on tech platforms' speech rights as the state law instead seeks to regulate the companies' conduct with regard to their users. Even if the law did raise First Amendment concerns, he argued, those concerns are adequately addressed by the fact that HB 20 seeks to define social media companies as "common carriers" akin to phone companies and railroads.

The dozen states who authored the filing defending the law argued that HB 20 is intended to protect the speech of social media users and that platforms' speech interests are not harmed by the legislation. "Social media platforms remain free and perfectly able to speak with their own voice on any issue both on their own platforms and outside them," the states argued.

The case has already drawn "friend of the court" briefs from interested third parties including groups such as the Anti-Defamation League and the Texas State Conference of the NAACP, who urged the court to block the law, arguing it will "transform social media platforms into online repositories of vile, graphic, harmful, hateful, and fraudulent content, of no utility to the individuals who currently engage in those communities."

Also seeking to file a third-party brief was former Rep. Chris Cox, co-author of the tech platform liability shield known as Section 230 of the Communications Decency Act, a federal law that explicitly permits websites to moderate content and which has become a lightning rod in the wider battle over digital speech.

Social media operators have repeatedly cited Section 230 to successfully nip many suits in the bud concerning user-generated content. But HB 20 conflicts with Section 230 by saying platforms can be sued in Texas for moderating their online communities, raising questions about the future of the federal law that's been described as "the 26 words that created the internet."

On Saturday, Alito gave Texas a deadline of Wednesday evening to file its response to the stay request. He may either make a unilateral decision on the stay, or refer the decision to the full Court.