WASHINGTON (Reuters) - Conservative Justice Clarence Thomas on Tuesday urged the U.S. Supreme Court to reconsider its landmark 1964 ruling that made it harder for public figures to sue for defamation, a precedent that has served as powerful protection for the news media.

FILE PHOTO: Actor and comedian Bill Cosby arrives at the Montgomery County Courthouse for sentencing in his sexual assault trial in Norristown, Pennsylvania, U.S., September 25, 2018. REUTERS/Brendan McDermid/File Photo

Thomas took aim at the unanimous ruling in the libel case known as New York Times Co. v. Sullivan in an opinion he wrote concurring with the court’s decision to end a defamation suit against Bill Cosby filed by a woman who said the comedian raped her in 1974.

Thomas, one of the high court’s most conservative justices, said the 55-year-old decision was not rooted in the U.S. Constitution. That ruling and subsequent ones extending it “were policy-driven decisions masquerading as constitutional law,” Thomas wrote, expressing views in harmony with President Donald Trump, who often attacks the media and has advocated making it easier to sue news organizations and publishers for defamation.

Thomas agreed with his fellow justices in refusing to consider reviving a defamation lawsuit against Cosby by Kathrine McKee, an actress and former Las Vegas showgirl who said the entertainer falsely called her a liar after she accused him of rape.

McKee was represented in the case by attorney Charles Harder, who represented Trump in a defamation suit brought against the president by adult film actress Stormy Daniels. Daniels has said she had a sexual encounter with Trump in 2006, which he denies. McKee had appealed a court ruling in Massachusetts that threw out her lawsuit.

The New York Times v. Sullivan ruling has served as a safeguard for media reporting on public figures.

Trump in January 2018 called current defamation laws “a sham and a disgrace” following the publication of a book about the White House by author Michael Wolff called “Fire and Fury: Inside the Trump White House,” which among other things questioned the president’s mental health.

The high court’s 1964 ruling held that in order to win a libel suit, the plaintiff must demonstrate that the offending statement was made with “actual malice,” meaning knowledge that it was false or reckless disregard as to whether it was false.

The case involved a lawsuit against the New York Times, a newspaper that Trump often criticizes for its coverage of him.

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Thomas wrote that “we should carefully examine the original meaning of the First and Fourteenth Amendments,” referring to the constitutional provisions protecting freedom of speech, freedom of the press and the application of those rights to the states.

“If the Constitution does not require public figures to satisfy an actual-malice standard in state-law defamation suits, then neither should we,” Thomas wrote.

Thomas said defamation law was historically a matter for the states, and should remain that way.

“The states are perfectly capable of striking an acceptable balance between encouraging robust public discourse and providing a meaningful remedy for reputational harm,” Thomas wrote.

None of the other eight justices joined Thomas in his opinion.

COSBY PRISON SENTENCE

Cosby, 81, was convicted in April 2018 of three counts of aggravated indecent assault for the drugging and sexual assault of Andrea Constand, a former Temple University administrator, in 2004. He was sentenced last September to three to 10 years in prison.

The Supreme Court last October snubbed Cosby’s appeal in another defamation case, allowing a lawsuit by former model Janice Dickinson to go forward against the entertainer best known for his starring role in the 1980s hit television series “The Cosby Show.”

McKee went public with her rape accusation in a 2014 interview with the New York Daily News. She is one of more than 50 women who have accused Cosby of sexual assault dating back to the 1960s by using drugs to incapacitate them.

An attorney for Cosby then sent a letter to the newspaper, suggesting McKee was a liar and calling her an unreliable source. In the letter, Cosby’s lawyer said McKee had admitted lying to get hired as a showgirl.

McKee sued Cosby for defamation in 2015 in federal court in Boston, saying the letter made false statements and harmed her reputation.

A trial judge in 2017 dismissed her claims, saying the lawsuit was barred by the First Amendment guarantee of free speech. The Boston-based 1st U.S. Circuit Court of Appeals upheld that ruling.

The appeals court said that by deliberately wading into the controversy, McKee had become a public figure, requiring her to prove Cosby acted with malice to win a defamation claim.

McKee told the justices that she “should not be victimized twice over” by making it harder for her to prove defamation merely because she went public as an alleged victim.