The Supreme Court on Tuesday put on hold a Texas law that bars social media companies from removing posts based on a user’s political ideology while a legal battle over whether such measures violate the First Amendment continues in lower courts.

The vote was five to four. Justice Samuel Alito Jr., joined by Justices Clarence Thomas and Neil Gorsuch, said he would have allowed the law to go into effect. Justice Elena Kagan would have let a decision from the lower court stand for now but did not detail her reasoning.

Two Washington-based groups representing Google, Facebook and other tech giants filed the emergency request with the Supreme Court on May 13. The Texas law took effect after a divided panel of the U.S. Court of Appeals for the 5th Circuit lifted a district court injunction that had barred it.

The appeals court’s order, which did not specify its legal reasoning, shocked the industry, which has been largely successful in batting back Republican state leaders’ efforts to regulate social media companies’ content moderation policies.

Texas and Florida are two states with such laws, which they said were necessary to combat the tech industry’s squelching of conservative viewpoints.

On Monday, a unanimous panel of the U.S. Court of Appeals for the 11th Circuit said that much of Florida’s law violated the First Amendment, ruling that social media companies’ efforts to curate the content of their platforms was speech that the government could not control.

In a detailed, 67-page opinion, the three judges – all appointees of Republican presidents – unanimously rejected many of the legal arguments that conservative states have been using to justify laws governing the moderation policies of major tech companies after years of accusing the tech companies of bias against their viewpoints.

The tech companies similarly have called the Texas law “an unprecedented assault on the editorial discretion of private websites (such as Facebook.com, Instagram.com, Pinterest.com, Twitter.com, Vimeo.com, and YouTube.com) that would fundamentally transform their business models and services,” according to the Supreme Court application filed by two organizations, NetChoice and the Computer and Communications Industry Association.

The organizations hired a former U.S. solicitor general and two former Texas solicitors general to take the case to the Supreme Court.

The petition cited “serious First Amendment problems with these novel state efforts to regulate a global phenomenon” that should be fully litigated before the Texas law goes into effect.

In their filing to the Supreme Court, NetChoice and CCIA argue that the law is unconstitutional and risks causing “irreparable harm” to the Internet and businesses.

“While the Judiciary cautiously reviews these momentous issues, platforms should not be compelled by government to disseminate the vilest speech imaginable – such as white supremacist manifestos, Nazi screeds, Russian-state propaganda, Holocaust denial, and terrorist-organization recruitment,” the petition said.

Texas Republican Attorney General Ken Paxton noted that the Supreme Court has said social media sites are gatekeepers of a digital “modern public square.” He said the state law is focused on businesses’ conduct and does not violate the First Amendment, which protects private companies from government regulation of speech.

Because they are the “twenty-first century descendants of telegraph and telephone companies,” the businesses should be treated as “common carriers,” which are subject to government regulation because of the essential nature of the services they offer, Paxton said.

Tech companies aggressively lobbied against the Texas law and similar legislation in other states, and they were initially successful in their legal challenge to the Texas law, as a federal district judge blocked its implementation.

The tech industry has warned that the Texas law opens companies up to new legal threats that could chill their efforts to remove objectionable content including terrorism and violence, such as the recent videos circulating on social media of the Buffalo shooting.

Meanwhile, Texas Republican Gov. Greg Abbott and Republicans who crafted the law have argued that it will prevent conservative viewpoints from being banned on social media.

The Supreme Court’s response is being closely watched by policymakers who are eager to regulate social media but whose proposals have collided with the free-speech protections afforded by the First Amendment.

The Texas law was signed in September amid an escalating debate over how the world’s largest tech companies should police their platforms. Democrats have argued that the companies need to be more aggressive – especially in the wake of the pandemic, a national reckoning on race and the 2020 election – in stopping the spread of disinformation and hate speech.

Republicans say these efforts have gone too far, having a “censoring” effect on political speech. Despite repeated hearings with company executives and a flurry of proposed bills, Congress has not passed any comprehensive legislation regulating social media companies since the 1990s.

Out of power in Washington and angered by tech platforms’ decisions to suspend former President Donald Trump’s account in the fallout of the Jan. 6, 2021, attack on the U.S. Capitol, Republicans have increasingly turned to state houses to address their long-running accusations that Silicon Valley companies are biased against their political views. Attacks on the tech industry have become central to the party’s political messaging and fundraising during the 2022 midterm elections.

A dozen states have filed an amicus brief supporting Texas, signaling how other states could be emboldened to pass their own social media regulations.