Outspoken anti-Trump actor Robert De Niro dropped a pair of f-bombs when asked about Fox News during a conversation about President Trump in a vulgar CNN appearance on Sunday that has critics wondering what he was doing on the liberal network in the first place.

A current CNN on-air personality who spoke on condition of anonymity questioned the decision to book De Niro.

“It’s particularly puzzling that our show, which allegedly critiques media, would choose to host a Hollywood celebrity with zero discernible news value,” the CNN employee said. “What is his credential, other than deeply hating the president? What did our viewers gain from his vulgarity?”

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“It’s particularly puzzling that our show, which allegedly critiques media, would choose to host a Hollywood celebrity with zero discernible news value." — CNN on-air personality

The 76-year-old De Niro appeared on CNN’s media show “Reliable Sources” with host Brian Stelter, who told the Hollywood legend that the liberal network had been trying to book him “for a while.” De Niro is famous for his tough-guy shtick and has used profanity to attack Trump in the past, including famously launching a salty tirade at the president during the 2018 Tony Awards.

During his live CNN appearance, De Niro called the president “crazy” and didn’t disappoint fans of his iconic gangster flicks when he was asked about pundits on Fox News who support Trump.

“F--- ‘em, f--- ‘em,” De Niro said.

The Hill media reporter Joe Concha feels the situation was “contrived” because CNN has allowed profanity on its air in the past and De Niro is known for using vulgar language when speaking about President Trump. CNN has not distanced itself from the interview and even promoted it on social media and its website.

A second CNN personality, also speaking on the condition of anonymity, said they would have quickly ended the interview when De Niro used profanity but admitted it was probably a win for the network because of the publicity it generated.

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“I would have said, ‘We’re done here,’ but entitlement culture comes from people who are icons in their trade, they think they can get away with that on a Sunday morning,” the source said. “But if it’s good for ratings you can deal with the blowback.”

"If it’s good for ratings you can deal with the blowback.” — Second CNN personality

Stelter, unlike his colleague, did not immediately apologize for the language and noted that it was on cable so the comment wouldn’t result in an FCC violation. “But it is still a Sunday morning,” Stelter said. “Why do you choose to go that way?”

Ironically, De Niro responded that Trump behaves “like a gangster” and said America is in a “terrible” situation as a result. After a commercial break, Stelter pivoted the conversation to De Niro’s upcoming gangster movie, “The Irishman,” but the duo inevitably turned their focus back to Trump.

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De Niro said that Trump “makes gangsters look bad” because actual mobsters “keep their word.” Stelter, who has been outspoken with his criticism of Trump himself, thanked De Niro for appearing and wrapped up the segment. He never commented further on the profanity.

A CNN spokesperson directed Fox News to a Twitter exchange between Stelter and a National Republican Senatorial Committee staffer when asked why the partisan actor was booked on a media show.

“Interviewing one of the best-known actors in the world falls squarely within the purpose, which is (as I say most Sundays) to explore ‘how the media world works, how the news gets made,’” Stelter tweeted when asked the purpose of his show in the first place.

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“So his reliability as a reliable source on key issues like impeachment and the President’s mental health is based solely on his status as a celebrity? Just wanted to make clear that was the calculus,” NRSC staffer Matt Whitlock fired back at the “Reliable Sources” host.

NewsBusters managing editor Curtis Houck told Fox News that the CNN media show is “as close to a sermon for the Resistance as one will get” and De Niro's appearance was nothing different.

"Stelter feigned discomfort for what happened, but in reality, CNN couldn't be any prouder of how that went down. De Niro's tirade illustrated why any lecture from [CNN] about civility and decency will continue to ring hollow,” Houck said. “The desire to impeach the president has become such an obsession for CNN and the rest of the liberal media that it's become a 21st-century version of the golden calf that these people worship.”

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De Niro – who has played former Special Counsel Robert Mueller on NBC’s “Saturday Night Live – once urged Mueller to speak out against Trump in an open letter published by the New York Times. The Oscar-winning actor has also called Trump a “total loser,” a “f---ing idiot,” “f---ing fool” and said he would like to punch the president in the face.

“No Things Considered” host and political satirist Tim Young also questioned why the actor was booked on CNN’s media show.

"I'm not sure how Robert De Niro is a ‘reliable source,’ or what he would even be a reliable source on. He didn’t talk Hollywood, he was brought on to rant and swear about why he hates Trump,” Young told Fox News before joking, “Oh, I get it, maybe he was a reliable source on Trump Derangement Syndrome.”

DePauw University professor and frequent CNN critic Jeffrey McCall told Fox News: “We live in a weird time in which pop culture blends with public affairs,” but even with that consideration, there is no journalistic purpose to putting somebody like De Niro on “what is supposed to be a serious” show about media and public affairs.

“The producers, including Stelter, just had to know that De Niro would go on television and cut loose with verbal brickbats and that's what they got," McCall said. "Having Hollywood types on news programs to discuss national policy is a problem from the outset, but having an actor who has a history of strident and profane outbursts just further disrupts public dialogue.

“The problem with this interview is not just the foul language, but also the angry and emotional tone that permeates the discussion,” McCall continued. ‘De Niro clearly detests Trump, which he has a right to do, but Stelter needed to guide the discussion into something that might generate meaningful insight… this interview was not good television or good journalism. It simply fuels public disenchantment with how the media does its job, allowing emotion and polarization into what needs to be rational dialogue.”

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Media Research Center vice president Dan Gainor mocked the interview on Twitter, writing that “Reliable Sources” is “just left-wing activism” and noting that actual “journalists” don’t care what De Niro thinks of Trump.

Stelter responded, “But this journalist, no quote marks, does.”

New York Post columnist Karol Markowicz summed up the feelings of many with her response to the CNN host, “But that's because you knew what he would say and that you agree with him. Where's the journalism in that? What did you discover?”

Fox News’ Joseph A. Wulfsohn contributed to this report.