WASHINGTON (CNN) — The Supreme Court on Monday appeared to have deep concerns of state laws enacted in Florida and Texas that would prohibit social media platforms from throttling certain political viewpoints.

The high-stakes battle gives the nation’s highest court an enormous say in how millions of Americans get their news and information, as well as whether sites such as Facebook, Instagram, YouTube and TikTok should be able to make their own decisions about how to moderate spam, hate speech and election misinformation.

“The First Amendment restricts what the government can do,” said Chief Justice John Roberts. “What the government’s doing here is saying ‘you must do this, you must carry these people – you’ve got to explain if you don’t. That’s not the First Amendment.”

The state laws ban online platforms from removing posts that express opinions, such as political content. States say the laws are necessary to keep the social media platforms from discriminating against conservatives.

At least at this stage of the case, however, it’s unclear how the justices will rule. Several of the justices were unsettled by the possibility that the laws could be applied to other sites, like Uber, without violating the Constitution. Some of the nine, meanwhile, signaled a desire to send the case back down to lower courts for further review about the potential sweep of the laws’ provisions beyond the social media platforms.

One of the central themes of debate that emerged during the course of the arguments was whether social media companies are engaged in First Amendment-protected activity when they moderate content, such as by deplatforming users for posting misinformation or hate speech.

The arguments appeared to divide at least some of the court’s conservatives. Justice Samuel Alito pressed a lawyer representing the Biden administration on why, when a social media company throttles a view, that shouldn’t be described as “censorship” rather than “content moderation.”

Alito worried about resisting “the Orwellian temptation to recategorize offensive conduct in seemingly bland terms.”

Justice Brett Kavanaugh, a fellow conservative whose questions seemed to indicate support for the tech companies, responded by noting that the First Amendment’s prohibition on barring speech applies to government action, not action taken by private companies.

“When I think of ‘Orwellian,’ I think of the state – not the private sector, not private individuals,” Kavanaugh said. “Maybe people have different conceptions of ‘Orwellian.’’’

More than a dozen Republican attorneys general say the government should treat social media like the phone companies and other utilities. But the tech industry says it’s more like newspapers or cable companies, deciding what to put out into the world.

The case could lead to a significant rethinking of First Amendment principles, according to legal experts. A ruling in favor of the states could weaken or reverse decades of precedent against “compelled speech,” which protects private individuals from government speech mandates, and have far-reaching consequences beyond social media.

Questions on Florida law

Supreme Court justices opened Monday’s oral arguments by questioning Florida Solicitor General Henry Whitaker about the broad scope of the state’s law restricting content moderation.

Justice Sonia Sotomayor said Florida’s law could prevent the online marketplace Etsy from curating items sold by its users.

“This is so, so broad, it’s covering almost everything” on the internet, Sotomayor said. “But the one thing I know about the internet is that its variety is infinite.”

Etsy necessarily has to be able to curate what it shows users or else they would be overwhelmed by the variety, Sotomayor said.

Whitaker said Florida’s law is limited by its definition of social media companies, which focuses on large platforms.

In addition to Etsy, other justices pushed Whitaker to play out how sites including Facebook and LinkedIn could be affected by the Florida law’s breadth.

“What do you do with [the scenario of], LinkedIn has a virtual job fair, and it has some rules about who can be involved?” Justice Ketanji Brown Jackson asked. She also pushed Whitaker to say how Florida’s law might affect Facebook’s news feed differently from other parts of its platform.

Whitaker took the broad position that Florida’s law wants to treat platforms as “common carriers,” a regulatory designation that has applied to telecom companies and railroads. That would mean, he said, that the justices would not need to address many of the hypotheticals being raised by the court, because that designation would preempt a debate about the First Amendment.

Impact on other tech companies

Justice Amy Coney Barrett sounded a skeptical note on Florida’s law, echoing her colleagues on its breadth.

“Florida’s law, so far as I can understand it, is very broad,” Barrett said, ticking off still other companies that could be affected. “We’re talking about the classic social media platforms, but it looks to me like it could cover Uber. It looks to me like it could cover Google’s search engine, Amazon Web Services. And all of those things would look very different.”

Earlier, Barrett and Kavanaugh zeroed in on a key issue in the case: Whether the First Amendment prevents states from forcing private businesses to host others’ speech.

Kavanaugh told Whitaker Florida’s argument had “left out” that the First Amendment restricts governments, not businesses.

Barrett asked Whitaker to explain how social media platforms were not like newspapers or bookstores.

“Could Florida enact a law telling bookstores that they have to put everything out by alphabetical order, and that they can’t organize or put some things closer to the front of the store that they think you know, their customers will want to buy?” Barrett asked.

Whitaker said social media platforms had opaque algorithms that prevent users from fully understanding how content curation happens.

Could the Florida law prevent Gmail from deleting or sending to spam emails sent by political commentators such as Tucker Carlson or Rachel Maddow? Justice Samuel Alito asked Paul Clement, the tech industry’s attorney.

Clement said the Florida law would seem to cover Gmail. Conservative groups have alleged that Gmail has engaged in partisan censorship by relegating certain campaign emails to spam – allegations the Federal Election Commission has tossed out.

Kagan cited X, the platform formerly known as Twitter, as evidence that social media platforms do engage in speech when they moderate content.

Highlighting how the tone and range of content shifted on Twitter after Elon Musk bought the company in October 2022, Kagan said “a lot of Twitter users thought that was great. And a lot of Twitter users thought that was horrible.”

X has been under fire from advertisers, lawmakers and civil rights groups over its handling of hate speech and other offensive material after Musk laid off huge swaths of the company’s staff in the weeks after the takeover.

Could parts of Florida’s law survive?

Even if some parts of the Florida law are unconstitutional, perhaps some of its provisions might pass First Amendment scrutiny, some of the justices suggested.

“It might be OK,” Sotomayor hypothesized, if a website were required to provide more transparency to users of direct messaging or to enforce their terms equally, or provide enough notice to users of changes in policies.

“All it’s saying is that when you run a service where you’re not speaking… when you’re running Venmo, you’re not engaged in speech activities,” Kagan suggested.

Clement disagreed with that characterization, saying that Florida’s law “is shot through” with unconstitutional provisions that target the content of online speech, meaning the whole law must fall. Clement warned of significant disruption to social media if the court sided with the states.

“If this statute goes into effect, we sort of have to fundamentally change our business models,” Clement told the court.

Some platforms may decide to allow “only puppy dogs” on their social media sites to avoid being perceived as discriminating against speech, Clement said.

More seriously, he said, “these laws make it impossible for us to keep material that’s harmful to children off of our sites, unless we take so much material off of our sites that nobody can [accuse the sites of] viewpoint discrimination.”

Federal opposition to Florida and Texas laws

The US government opposes the Texas and Florida laws as unconstitutional restrictions on private platforms’ own “expressive product,” US Solicitor General Elizabeth Prelogar told the court.

“Normally you are defending regulations,” Justice Clarence Thomas observed dryly, as he asked Prelogar to explain how companies moderating content was different from unconstitutional government censorship.

“These are websites featuring text elements, speech elements, photos, videos, and the platforms, which are private parties not bound by the Constitution, are deciding how they want that to look — what content to put on it, and in what order,” Prelogar said. “That’s an inherently expressive act.”

She added: “The critical difference here, of course, is that these platforms are private parties, they’re not bound by the First Amendment.”

Even though the Biden administration said Florida’s law is unconstitutional, it differed from the industry on how far the law tries to go. The court may not need to assume that the Florida law extends so broadly, the Biden administration’s attorney told the justices.

Direct messages on social media and email are more like the telegraph than news feeds and public content curation, Prelogar continued, diverging from the tech industry’s position.

“If I were the court, I would really want to reserve judgment on application to ecommerce sites, to companies like Uber, which don’t seem to be creating a comparable type of expressive product,” Prelogar said, “and I think the court can save those issues for another day or for further factual development in this case.”

“I do think there would be a lot of value, though, in the court making clear” that Florida trying to control social media companies’ editorial choices is unconstitutional, Prelogar said.

Sotomayor appeared to acknowledge a key claim by the tech industry, which was that social media platforms do engage in expression in a variety of ways.

“I think what’s clear is from our questioning … that there are many functions that are expressive,” Sotomayor told Prelogar. In that respect, Sotomayor said, social media companies are not like the telegraph as Whitaker had suggested.

Section 230 as a “landmine”

Section 230 of the Communications Decency Act could potentially trip up the court as it seeks to address the state laws at issue in Monday’s arguments, Barrett said.

Section 230 is a hotly debated federal law that shields tech platforms from lawsuits related to content moderation. It has been broadly interpreted by the courts to protect websites’ ability to determine what content to display or remove.

How the court rules in these cases this week could affect the scope of Section 230 and shape the circumstances under which social media platforms could be sued.

“If what we say about this is that this is speech that’s entitled to First Amendment protection, I do think then that has Section 230 implications for another case,” Barrett said. “And so it’s always tricky to write an opinion when you know there might be landmines that would affect things later.”

Social media would change in other ways if the states’ laws are ultimately upheld, Clement warned as arguments began on the Texas law.

“We basically have to eliminate certain areas of speech entirely,” Clement said. “So we couldn’t talk about suicide prevention anymore, because we’re not going to talk about suicide promotion. I guess we couldn’t have pro-Semitic speech, because we’re not going to have anti-semitic speech.”

“Suppose you wanted to prevent anti-semites from posting anything… we’re not even going to let them post cat videos. Should we think about that set of applications differently?” Kagan asked.

As part of a longer answer to multiple justices, Clement said the First Amendment is intended to protect private parties’ desire to exclude people from conversation.

If a Catholic website wanted to exclude a Protestant from participating in a discussion, the First Amendment shields that website’s ability to do that, Clement said, prompting widespread laughter in the courtroom.

“It’s a private forum, and the government can’t tell me as a private party, let the Protestant into the Catholic party,” Clement said.