WASHINGTON ― The White House on Thursday defended disseminating a manipulated video identical to one posted by a conspiracy theory website that has falsely claimed the Sandy Hook Elementary School massacre never happened.

The site, InfoWars, has been a longtime supporter of Donald Trump’s, and Trump has reciprocated the admiration with an interview when he was running for president. One noted presidential historian, meanwhile, called the episode a low point in White House press relations.

Press secretary Sarah Huckabee Sanders posted the 15-second clip on her Twitter account late Wednesday night as justification for banning a CNN reporter who asked questions that President Donald Trump did not like. After Trump told Jim Acosta “That’s enough, that’s enough,” a White House intern tried to grab a microphone away from the reporter.

White House press secretary Sarah Huckabee Sanders sent out this manipulated video on her official White House Twitter account late Wednesday night.

The identical 15-second clip had been posted two hours earlier by an InfoWars editor. It shows the incident in wide-angle view, and then five more times in close-up.

Sanders announced in a press release distributed at 8 p.m. Wednesday ― and in a series of five tweets posted a few minutes earlier ― that the White House was confiscating Acosta’s Secret Service-issued press credentials that permit entry into the White House complex. Her statements came about a half hour after Diamond and Silk, two YouTube-based Trump supporters, advocated that Acosta’s badge be pulled during an appearance on the Fox Business channel.

Trump is known to watch a great deal of cable television, especially Fox channels, and to make decisions apparently based on that information.

The White House did not respond to multiple queries about the origin of the video. Nor did it say whether the urging by Diamond and Silk played a role in the decision to punish Acosta.

It also would not explain why press officers managing Wednesday’s news conference asked the intern to try to wrestle the microphone away from Acosta, rather than just turning it off remotely from the board that controls the audio.

Douglas Brinkley, a presidential historian at Rice University, called the White House’s response “unprecedented” in the modern era. “This is President Trump targeting Acosta because he asks tough questions. That’s not the way you’re supposed to be running a press operation,” he said.

Acosta responded almost immediately to Sanders’ statement on Twitter, calling it “a lie.” Shortly afterward, CNN said: “In an explanation, Press Secretary Sarah Sanders lied. She provided fraudulent accusations and cited an incident that never happened. Jim Acosta has our full support.”

The point of yesterday’s session was merely to antagonize Trump’s ... favorite bogeyman, the free press, in order to keep them galvanized and everyone else distracted in the wake of a stinging political defeat. Ned Price, a former official in the Obama administration

Why Trump even called on Acosta, whose reporting he has long complained about, is unclear. Ned Price, a spokesman for the National Security Council under President Barack Obama, said Trump’s intention at the press conference was clearly to rile up his political base after his party lost control of the House in Tuesday’s midterm elections.

“Had it been a true effort to inform the American public, the president would’ve announced the removal of his attorney general. Instead, he appears to have lied about it when asked,” Price said. “The point of yesterday’s session was merely to antagonize Trump’s and his supporters’ favorite bogeyman, the free press, in order to keep them galvanized and everyone else distracted in the wake of a stinging political defeat. Mission accomplished.”

In her statement Wednesday evening as well as a new one Thursday, Sanders claimed that Acosta’s credentials were pulled because of his interaction with the female intern who tried to take away the microphone.

“We will, however, never tolerate a reporter placing his hands on a young woman just trying to do her job as a White House intern. This conduct is absolutely unacceptable,” Sanders wrote Wednesday night.

On Thursday, she wrote: “The question is: Did the reporter make contact or not? The video is clear, he did. We stand by our statement.”

But a review of the video clearly shows that Acosta did not place “his hands on a young woman” ― but, rather, that he moved the mic away from her as she tried to grab it and that his left hand briefly came into contact with the crook of her elbow as he gestured toward the president.

InfoWars editor Paul Joseph Watson posted this to his Twitter account on Wednesday evening.

In the clip originally posted by InfoWars’ Paul Joseph Watson, the zoomed-in video stops as Acosta’s hand touches the intern’s arm, making that contact appear more forceful than it does in the longer wide-angle clip.

InfoWars did not respond to a HuffPost request for comment.

Aymann Ismail, a staff writer and former video producer at Slate.com, wrote that the zoomed-in video appears to slow down and then speed up, which also makes the contact appear more energetic than it was. He wrote later that the effect could have been the result of the video being downloaded and shifted to a different frame rate, rather than due to malicious editing.

InfoWars is a conspiracy theory site best known for claiming ― falsely ― that the 2012 Sandy Hook shooting was staged and that the 20 elementary school children and six staff gunned down there were actually alive and well somewhere. The site and its operator, Alex Jones, are being sued by parents of those children for defamation.

The site is also known for its sales of dubious vitamin supplements (“Brain Force Plus.” “Super Male Vitality.”) and is a strong supporter of Trump and white nationalist politics generally. Trump was interviewed by Jones in December 2015 when he was still just a candidate in the GOP presidential primaries. He told the conspiracy theorist, “Your reputation is amazing. I will not let you down.”

Brinkley said that not even President Richard Nixon, who famously mistrusted the news media, tried to pull credentials from reporters. Nixon limited access ― for example, he took only print journalists who had written favorable stories about him on his groundbreaking trip to China ― but he did not restrict individual journalists’ ability to do their jobs, Brinkley said.

Trump’s actions, the historian added, are entering uncharted territory. “It starts feeling like a banana republic,” he said.