WASHINGTON (Reuters) - Casino mogul Steve Wynn has asked the U.S. Supreme Court to hear an appeal that, if granted, could give the justices a chance to revisit libel protections for journalists enshrined in a landmark 1964 ruling that has been questioned by two conservative justices and President Donald Trump.

The court established a stringent limit on defamation claims by public figures more than 60 years ago in its New York Times v. Sullivan decision involving the U.S. Constitution's First Amendment protections for freedom of speech and the press.

Wynn, the former CEO of Wynn Resorts ( WYNN ) and former finance chair of the Republican National Committee, is appealing a decision by Nevada's top court to dismiss his defamation suit against the Associated Press and one of its journalists. The court found Wynn failed to show a disputed 2018 news report containing allegations of sexual assault had been published with "actual malice."

The Supreme Court in New York Times v. Sullivan and subsequent decisions set a standard that in order to win a libel suit, a public figure must demonstrate the offending statement was made with "actual malice," meaning with knowledge it was false or with reckless disregard as to whether it was false.

That standard has since been adopted in a number of state laws across the country, including in Nevada.

Wynn's petition for appeal, which was made public by the court on February 4, asks the justices to assess "whether this court should overturn Sullivan's actual-malice standard," as well as a related prior court decision.

At least four justices must vote to grant review for the court to hear an appeal. No date has been set for the justices to review or vote on whether to take up Wynn's case.

Wynn's defamation lawsuit accused the defendants of publishing an article falsely alleging he committed sexual assault in the 1970s. Those claims first appeared in two separate citizens' complaints that an Associated Press reporter obtained from the Las Vegas Metropolitan Police Department, including one complaint that Wynn argued was implausible on its face and that a Nevada court in a separate proceeding found to have included "clearly fanciful or delusional" allegations.

Wynn has denied the sexual assault allegations.

The Supreme Court in recent years has turned away other opportunities to revisit New York Times v. Sullivan, including a 2021 denial that drew dissents from conservative Justices Clarence Thomas and Neil Gorsuch.

Citing a rapidly changing media environment increasingly rife with disinformation, Thomas and Gorsuch said in separate opinions the court should take a fresh look at its precedents that make it harder for public figures to sue for defamation.

Since launching his first Republican presidential campaign in 2015, Trump has often attacked and even sued media outlets whose coverage he dislikes, and has repeatedly criticized U.S. defamation laws.

A federal judge in 2023 threw out Trump's $475 million defamation lawsuit against CNN, in which the former president claimed the network's description of his election fraud as the "big lie" associated him with Adolf Hitler. Trump's lawyers, in a 2022 filing in that case, had invited the judge to reconsider the legal standard set in New York Times v. Sullivan.

"The court should reconsider whether Sullivan's standard truly protects the democratic values embodied by the First Amendment, or, instead, facilitates the pollution of the 'stream of information about public officials and public affairs' with false information," Trump's lawyers wrote.