When President Trump, or one of the aides manning his Twitter account, decided recently to retweet a mini video clip that appeared to show him pelting Hillary Clinton with a golf ball, it may not have only served as a crude joke about how he dunked his former Democratic rival in the election.

The graphic was originally posted by a Twitter user going by the name "CNN Sucks," and there's a high possibility that someone in the White House was just as moved by that detail as the video itself.

No one loves to hate CNN more than Trump.

Though Trump ran against the national media at-large and has continued his broadsides against the "fake news," a catch-all term for any story or journalist he doesn't like at any moment, he's held a particular antipathy for CNN.

The reason is not fully clear, though many CNN insiders say his angst mostly stems from feeling backstabbed by the network's chief executive, Jeff Zucker.

The two share a personal relationship dating back more than a decade when Zucker, then president of NBC Entertainment, cast Trump as star of "The Apprentice" when it launched in 2004.

Zucker also attended Trump's 2005 wedding to now-first lady Melania.

"The answer is that he feels betrayed by Jeff Zucker because Zucker was the boss at NBC," one CNN source told the Washington Examiner on condition of anonymity. "And he feels like ‘The Apprentice' boosted NBC, and he made a lot of money for NBC, and he made a lot of money for Zucker. Because the coverage [on CNN during the election] wasn't positive or laudatory, it genuinely took Trump by surprise. He thought his friend would have his back."

The New York Times reported in April that Trump, through his spokeswoman, reached out to Zucker after the second presidential debate in the general election.

"Jeff — Too bad you (CNN) couldn't be honest with how well I did in the debate," Trump said at the time in a letter. "The dumbest thing I ever did was get you the job at CNN — you are the most disloyal person. Just remember, I always seem to find a way to get even. Best wishes, Donald J. Trump."

The White House declined to comment for this story.

Other villains pop up, but only CNN remains

Trump is said to put a premium on loyalty among his associates, even from people who might not necessarily see themselves as personally close to him.

In February of last year, well into the Megyn Kelly-Trump feud, Kelly, then still a Fox News anchor, reflected on her loose acquaintance with Trump, a prelude to his lashing out at her during the Republican primary debate she co-moderated and his assertion that she had "blood coming out of her — wherever."

She told Vanity Fair that prior to the election, helming "The Kelly File" in Fox's prime-time lineup, Trump would occasionally reach out to her, unprompted.

"He would send me press clippings about me that he would just sign ‘Donald Trump,' " she said. "And he called from time to time to compliment a segment. I didn't know why he was doing that. And then, when he announced that he was running for president, it became more clear. But I can't be wooed."

Later on, when Kelly, at the Fox-hosted GOP primary debate, confronted Trump with a series of past comments he had publicly made about some women, he seemed genuinely put off.

"What I say is what I say," he answered. "And honestly, Megyn, if you don't like it, I'm sorry. I've been very nice to you, although I could probably maybe not be, based on the way you've treated me, but I wouldn't do that."

From there, the friction intensified. Trump had a mini-war with Fox News, casting the whole network's coverage as unfair. He withdrew from a debate the network hosted in January last year, calling the event a "bad deal." Instead, he hosted a charity fundraiser for veterans.

But that feud passed and now, Trump frequently tweets out praise for Fox, the channel's morning program "Fox & Friends" in particular.

Trump has picked fights with other reporters and other organizations, but no other news outlet has had to sustain Trump's heat like CNN.

NBC reporter Katy Tur, for example, became a minor cable news celebrity covering Trump's campaign. He once called her out by name in a rally in South Carolina as "Little Katy."

"Taunted by Trump, ‘Little Katy' stood her ground. And became a star because of it," read a January headline in the Washington Post.

Trump doesn't talk about her or NBC much anymore. (Tur recently authored a book about her experience covering Trump's campaign, a common pattern among reporters who have tangled with the reality TV start-turned-president or prominent members of his White House.)

Trump also has a long-running feud with MSNBC "Morning Joe" co-hosts Mika Brzezinski and Joe Scarborough, most memorably tweeting in June that she had visited his Florida Mar-a-Lago resort and was "bleeding badly from a face-lift." (She admitted that she had previously had her "chin tweaked.")

Yet, the controversy subsided, and even that episode didn't rise to the level of near obsessive commentary Trump has dedicated to CNN.

Trump has mentioned CNN 438 times on Twitter, going back to 2010, two years before Zucker took over.

Early in the GOP primary, CNN often carried Trump's mega-campaign rallies live from beginning to end. Trump also frequently called into the network's shows for interviews.

"Zucker and Trump spoke every month or so during the Republican primaries," the New York Times reported in April. "CNN's anchors — [Jake] Tapper in particular — did some of the toughest interviews with Trump, who would sometimes call Zucker afterward to complain, often going on expletive-laden rants."

Other reasons

But the tension between Trump and CNN doesn't seem exclusively related to his relationship with Zucker.

The network's coverage of his administration apparently irks him in a particular way, which could be because of Zucker, but it could also be CNN's unique delivery in reporting the news.

"It's generally negative," Jeffrey Lord, a conservative writer, former CNN contributor, and a supporter of Trump, told the Washington Examiner. "It's pretty stark when you go back and forth between CNN and Fox, for example. The difference is pretty stark. I do think there's a lot of negative spin on stories [at CNN]."

CNN dismissed Lord as a commentator in August after he suggested that one of his critics on social media was mimicking Nazi Germany behavior. "Sieg Heil!" Lord tweeted in his response to the critic, an executive at the liberal Media Matters for America nonprofit. The remark was sarcastic, but it upset management.

"The media in general — as my dismissal from CNN illustrates to me — there is a liberal bent there, and people can criticize the president or Trump supporters as Nazis. But the moment you point out that a liberal group is using Nazi behavior, that's verboten," he said. "So, there is that kind of liberal reflex in the media at CNN, but obviously at others as well."

CNN pioneered the trend of fact-checking Trump and his administration officials using the lower-screen title graphics that appear live on air.

While airing a portion of an interview Trump granted to Fox News in June, CNN ran a graphic on the lower screen that said, "Trump: I never said Japan should have nukes (he did)."

The parenthesis was a cute way (some said too cute) of rebutting Trump's comments. Trump had actually said that Japan might be "better off" if it had nuclear weapons to defend itself from North Korean hostilities.

Two months later, CNN used a similar technique to fact-check Trump on an oft-repeated rhetorical campaign flourish about the Islamic State.

"Trump calls Obama founder of ISIS (He's not)," CNN's graphic said, interpreting Trump's comment as a literal assertion that Obama was really the founding father of a global terrorist network.

A prominent on-air source at CNN told the Washington Examiner that the pattern likely grated on Trump and his supporters.

"He watches TV nonstop," the source said of Trump's well-documented TV consuming habits. "And so the crawls and the banners on CNN, they've been getting bitchier and bitchier and negative toward him. He may not even see the programming in terms of what's being said, but he can see it because it's on at the White House. You can see the slant just based on what the graphics say."

CNN solidified its standing with Trump before he was even sworn into office when, in early January, the network broke the story of the salacious "dossier" containing unsubstantiated claims related to Trump's finances and personal life.

CNN published the story online just hours before Trump was scheduled to host a press conference. Though the article acknowledged the existence of the document and noted that top lawmakers had seen it, CNN did not publish its contents. BuzzFeed did, however, after CNN's report.

At the press conference that night, then-incoming White House press secretary Sean Spicer opened with a statement on CNN and BuzzFeed's "sad and pathetic attempt to get clicks."

When Trump spoke, he repeatedly said the news was "fake." When CNN's Jim Acosta tried to get a question in, Trump swatted it away.

"No, I'm not going to give you a question," he said, as Acosta kept pressing. "I'm not going to give you a question. You are fake news."

Since then, Trump has kept up a steady stream of invective, calling the network "fake news," "ratings challenged," and "embarrassed by their total (100%) support of Hillary Clinton" among other things.

In August, Trump retweed a graphic that showed a Trump-branded locomotive slamming into a CNN logo.

One month prior, he tweeted a clip from a cameo appearance he had in the past on a pro-wrestling program. In the original video, Trump slams a man to the ground. In the doctored one he shared on Twitter, the man's head was replaced with a CNN logo.

CNN declined to comment for this report.

Even when CNN isn't the direct target of one of Trump's tweeted insults, he often manages to slight the network before his 140 characters are spent.

"Just watched @NBCNightlyNews - So biased, inaccurate and bad, point after point," he said in one tweet in December. "Just can't get much worse, although @CNN is right up there!"

And since the press conference at which Trump refused to call on Acosta, the White House correspondent has made a name for himself for frequently switching between reporting and combative political commentary.

At a White House press briefing in early August, when the administration revealed a more selective legal immigration proposal, Acosta got into a snippy back-and-forth with White House policy adviser Stephen Miller.

When it was over, Acosta went for his on-camera live shot to claim victory. "'He couldn't take that kind of heat," he said of Miller.

Acosta's performances have, at times, bothered even some of his CNN colleagues. One at the network referred to Acosta as a "stunt dummy" in an article for the Washington Examiner last month.

Ned Ryun, a conservative activist who runs the American Majority nonprofit and who regularly serves as a political commentator on cable news, said it's those moments that are justifying Trump's antipathy for CNN.

"I just think part of it has been they have tried to position themselves as being more overtly antagonistic and so maybe that's why you see more against CNN than MSNBC or something like that," he said. "Acosta's questioning at the White House briefings, things like that, they really have singled themselves out by being more proactive in some of their antagonistic questioning. No desire to be objective at all."

The relationship seems miles away from November 2012, before Zucker was officially named head of the network. Trump weighed in on the network's leadership change.

"CNN is looking at Jeff Zucker to lead them out of the forest," Trump wrote. "Jeff would be a great choice."