WASHINGTON — The Supreme Court cast doubt Monday on state laws that could affect how Facebook, TikTok, X, YouTube, and other social media platforms regulate content posted by their users. The cases are among several this term in which the justices could set standards for free speech in the digital age.

In nearly four hours of arguments, several justices questioned aspects of laws adopted by Republican-dominated legislatures and signed by Republican governors in Florida and Texas in 2021. But they seemed wary of a broad ruling, with Justice Amy Coney Barrett warning of “land mines” she and her colleagues need to avoid in resolving the two cases.

While the details vary, both laws aimed to address conservative complaints that the social media companies were liberal-leaning and censored users based on their viewpoints, especially on the political right.

Differences on the court Wednesday emerged over how to think about the platforms — as akin to newspapers that have broad free-speech protections, or telephone companies, known as common carriers that are susceptible to broader regulation.

Chief Justice Roberts suggested he was in the former camp, saying early in the session, “And I wonder, since we’re talking about the First Amendment, whether our first concern should be with the state regulating what we have called the modern public square?”

Justices Samuel Alito and Clarence Thomas appeared most ready to embrace arguments made by lawyers for the states. Justice Thomas raised the idea that the companies are seeking constitutional protection for “censoring other speech.”

Justice Alito complained about the term “content moderation” that the sites employ to keep material off their platforms.

“Is it anything more than a euphemism for censorship?” he asked, later musing that the term struck him as Orwellian.

But Justice Brett Kavanaugh, seemingly more favorable to the companies, took issue with calling the actions of private companies censorship, a term he said should be reserved for restrictions imposed by the government.

“When I think of Orwellian, I think of the state, not the private sector, not private individuals,” Justice Kavanaugh said.

The precise contours of rulings in the two cases were not clear after arguments, though it seemed likely the court would not let the laws take effect. The justices posed questions about how the laws might affect businesses that are not the primary targets of the laws, including e-commerce sites like Uber and Etsy and email and messaging services.

The cases are among several the justices have grappled with over the past year involving social media platforms. Next month, the court will hear an appeal from Louisiana, Missouri and other parties accusing administration officials of pressuring social media companies to silence conservative points of view. Two more cases awaiting decision concern whether public officials can block critics from commenting on their social media accounts, an issue that previously came up in a case involving President Trump. The court dismissed the Trump case when his presidential term ended in January 2021.

The Florida and Texas laws were passed in the months following decisions by Facebook and Twitter, now X, to cut off Mr. Trump over his posts related to the January 6, 2021, attack on the U.S. Capitol by his supporters.

Trade associations representing the companies sued in federal court, claiming that the laws violated the platforms’ speech rights. One federal appeal struck down Florida’s statute, while another upheld the Texas law. But both are on hold pending the outcome at the Supreme Court.

In a statement when Governor DeSantis signed the Florida bill into law, he said the measure would be “protection against the Silicon Valley elites.”

When Governor Abbott signed the Texas law, he said that it was needed to protect free speech in what he termed the new public square. Social media platforms “are a place for healthy public debate where information should be able to flow freely — but there is a dangerous movement by social media companies to silence conservative viewpoints and ideas. That is wrong, and we will not allow it in Texas,” Mr. Abbott said.

But much has changed since then. Elon Musk purchased Twitter and, in addition to changing its name, eliminated teams focused on content moderation, welcomed back many users previously banned for hate speech, and used the site to spread conspiracy theories.

The Biden administration is siding with the challengers. Lawyers for Mr. Trump have filed a brief in the Florida case urging the court to uphold the state law.

Still, Solicitor General Elizabeth Prelogar, the administration’s top Supreme Court lawyer, cautioned the court to seek a narrow ruling that blocked the laws. Ms. Prelogar said governments maintain the ability to impose regulations to ensure competition, preserve data privacy, and protect consumer interests.

Several academics and privacy advocacy groups told the court that they view the laws at issue in these cases as unconstitutional, but want the justices to preserve the government’s ability to regulate social media companies to some extent.

Associated Press