Donald Trump dismissing his potentially lethal suggestion that coronavirus patients inject disinfectant as "sarcasm" isn't the first time he has downplayed dangerous or false claims after facing a backlash.

His use of "sarcasm" is "definitely taking advantage of the plausible deniability" while manipulating his supporters and undermining the media, according to Jennifer R Mercieca, associate professor of communication at Texas A&M University and the author of Demagogue for President: The Rhetorical Genius of Donald Trump.

The president's "sarcasm" is part of his rhetorical strategy on which he has relied for several years on the campaign trail and in the White House, she tells The Independent. Calling his own earnest remarks "sarcasm" and claiming the media has taken his words out of context plant enough seeds of doubt and distrust among his supporters.

His efforts to deflect blame ("I wasn't wrong, I was trolling you, it's not that I made a mistake, it's that you're too stupid to know the joke is on you", Prof Mercieca says) are "an absolute recipe for eliciting that outrage response" from his supporters while gaslighting his critics, she says.

Meanwhile, supportive media has rushed to his defence to interpret the meaning of his remarks, only to be undercut by the president days later when he says he was joking all along.

"It's poisonous," Prof Mercieca says. "There's no win for the public in that kind of cycle."

'The late, great Jimmy Carter'

In a wide-ranging, pre-campaign speech at the 2014 Conservative Political Action Conference, Mr Trump criticised then-president Barack Obama and said that his low polling numbers were similar to those of the "late, great" former president Jimmy Carter, who was in office from 1977 to 1981.

Mr Trump said: "We're getting into Jimmy Carter territory and I never thought I'd live to see anything like that again. I lived through that time and it was not a good time, and we're pretty close ... I think by next month we will have surpassed the late, great Jimmy Carter."

The former president, then 89, is still alive.

Mr Trump later said on Twitter: "Of course I don't think Jimmy Carter is dead - saw him today on T.V. Just being sarcastic, but never thought he was alive as President, stiff!"

"Russia, if you're listening, I hope you're able to find the 30,000 emails that are missing"

During a press conference at his Doral resort on 27 July 2016, then-candidate Trump discussed Hillary Clinton's email scandal, telling the room: "Russia, if you're listening, I hope you're able to find the 30,000 emails that are missing ... I think you will probably be rewarded mightily by our press. Let's see if that happens."

The remark wasn't tongue-in-cheek; nobody in the room was laughing. But the president later said he delivered it "in front of 25,000 people" as a "joke" and that "they" had cut off a video feed "so that you don't then see the laughter",

He told the Conservative Political Action Conference on 29 February: "Remember this thing, 'Russia, if you're listening'?' Remember, it was a big thing, in front of 25,000 people. 'Russia if you're...' It was all said in a joke."

The president added: "They cut that thing so quick at the end because they didn't want to hear the laughter in the place and me laughing. It was just 'boom.' These are really dishonest people."

At the 2016 press conference, he said he "hopes" that Russia has his political rival's emails. "They probably have her 33,000 emails that she lost and deleted because you'd see some beauties there," he said.

Asked on Fox & Friends the following day whether he was being sarcastic, Mr Trump said: "Of course. I'm being sarcastic."

Donald Trump celebrity president: A decade in two halves Show all 29 1 /29 Donald Trump celebrity president: A decade in two halves Donald Trump celebrity president: A decade in two halves Trump styles his 'You're fired!' pose in his Trump Tower office in June 2012. At the time he was known as a reality TV star on The Apprentice Diane Bondareff/Invision/AP Donald Trump celebrity president: A decade in two halves He was also well known as the patron of the Miss Universe competition Getty Donald Trump celebrity president: A decade in two halves Early signs of Trump's ambition for the presidency can be found everywhere. Not least in his 2011 book 'Time to get tough: Making America #1 again' Getty Donald Trump celebrity president: A decade in two halves Trump with Piers Morgan in November 2010. Piers Morgan has long held that he and Trump are good friends Getty Donald Trump celebrity president: A decade in two halves Trump appeared on Fox & Friends, his favourite show, in August 2011 Getty Donald Trump celebrity president: A decade in two halves Trump considered running in the 2012 election, where he would have faced Barack Obama. He is speaking here at an event for a Republican women's group Getty Donald Trump celebrity president: A decade in two halves Trump was subject to a Comedy Central roast in 2011. He is pictured here being roasted by rapper Snoop Dogg Getty Donald Trump celebrity president: A decade in two halves Given that this Trump store is in the lobby of Trump Tower, it can be said that Trump sells merchandise of himself out of his own home Getty Donald Trump celebrity president: A decade in two halves Trump held meetings with prominent Republicans when considering his 2012 bid. He is pictured here with Alaska governor Sarah Palin Getty Donald Trump celebrity president: A decade in two halves He didn't end up running in 2012 afterall, instead endorsing Republican candidate Mitt Romney AFP/Getty Donald Trump celebrity president: A decade in two halves Trump's golf course in Aberdeen proved controversial in 2012 when he began lobbying the Scottish government against wind power in order that they wouldn't install turbines off the shore by his new course Getty Donald Trump celebrity president: A decade in two halves He even gave evidence to a Scottish parliamentary committee discouraging wind energy AFP/Getty Donald Trump celebrity president: A decade in two halves He still found time for a round of course AFP/Getty Donald Trump celebrity president: A decade in two halves On 16 June 2015, Trump announced that he would run for the presidency of the United States in the 2016 election as a Republican Getty Donald Trump celebrity president: A decade in two halves His campaign was divisive, courting controversy wherever he went. Ultimately he was declared the Republican candidate in June 2016 Getty Donald Trump celebrity president: A decade in two halves Trump took part in the TV debate against opponent Hillary Clinton on 9 October Getty Donald Trump celebrity president: A decade in two halves Trump and wife Melania vote in the presidential election on 8 November 2016 AFP/Getty Donald Trump celebrity president: A decade in two halves Hillary Clinton conceded defeat at 2:50am on 9 November and president-elect Trump swiftly delivered his victory speech to a crowd of supporters Getty Donald Trump celebrity president: A decade in two halves News coverage around the world focused on the huge political upset that Trump's victory spelled AFP/Getty Donald Trump celebrity president: A decade in two halves Trump met with president Obama to discusss transition planning on 10 November. AFP/Getty Donald Trump celebrity president: A decade in two halves Donald Trump and Nigel Farage pose in the golden elevator at Trump Tower on 12 November 2016. Farage was the first British politician to meet with Trump after the election LeaveEUOffical/Twitter Donald Trump celebrity president: A decade in two halves The inauguration of Donald Trump took place on 20 January 2017. Trump's press secretary Sean Spicer boasted that the crowd was the 'largest ever' to witness an inauguration, a claim that was proved not to be true Getty Donald Trump celebrity president: A decade in two halves In his first 100 days as leader, Trump signed 24 executve orders, the most of any president AFP/Getty Donald Trump celebrity president: A decade in two halves One of Trump's most memorable election pledges was to build a wall between the US and Mexico. He is standing here in front of a prototype for a section of the wall Getty Donald Trump celebrity president: A decade in two halves Trump's meetings with other world leaders have provided no short supply of photo opportunities Getty Donald Trump celebrity president: A decade in two halves Trump was welcomed to the UK by the Queen and a state banquet was held at Buckingham Palace in his honour Reuters Donald Trump celebrity president: A decade in two halves Not everyone welcomed the president. Mass protests were held in London throughout his visits in both 2018 and 2019 EPA Donald Trump celebrity president: A decade in two halves One of the most significant meetings Trump has held with another leader was with North Korea's Kim Jong Un. In June 2019, Trump became the first sitting president to set foot in North Korea Getty Donald Trump celebrity president: A decade in two halves 2020 will see president Trump fight for a second term in office, who knows what the next decade will bring? Getty

Barack Obama and Hillary Clinton are the "founders of Isis"

In 2016, then-candidate Trump repeatedly claimed that his predecessor Barack Obama and Trump's Democratic challenger Hillary Clinton had founded terror group Isis.

He told the National Association of Home Builders: "I call President Obama and Hillary Clinton the founders of Isis. They are the founders."

The candidate also told supporters at a rally that Mr Obama is the founder "in a true sense".

Asked by conservative radio host Hugh Hewitt whether he meant that Mr Obama had "created a vacuum" for the terror group to emerge, Mr Trump responded: "No, I meant he's the founder of Isis."

At an August 2016 rally in Pennsylvania, Mr Trump — who had also perpetuated the "birther" conspiracy carried by a wave of racism and Islamophobia — claimed he was "being sarcastic" about his remarks but "not that sarcastic, to be honest with you."

He later wrote on Twitter: "Ratings challenged @CNN reports so seriously that I call President Obama (and Clinton) "the founder" of ISIS, & MVP. THEY DON'T GET SARCASM?"

"I am the chosen one"

On 29 August 2019, the president accused "any Jewish people that votes for a Democrat" of having "either a total lack of knowledge or great disloyalty". The next day, he shared a quote from far-right radio host Wayne Allyn Root, who said "the Jewish people in Israel love [Mr Trump] like he's the King of Israel. They love him like he is the second coming of God."

He said: "Thank you to Wayne Allyn Root for the very nice words."

Later that day, he addressed the looming trade war with China, telling reporters: "This isn't my trade war. This is a trade war that should've taken a long time ago with a lot of other presidents."

He added that "somebody had to do it" before turning his head to the sky and saying "I am the chosen one."

"Somebody had to do it," he said. "So I'm taking on China. I'm taking on China on trade. And you know what? We're winning."

He later wrote on Twitter: "When I looked up to the sky and jokingly said 'I am the chosen one,' at a press conference two days ago, referring to taking on Trade with China, little did I realize that the media would claim that I had a 'Messiah complex.' They knew I was kidding, being sarcastic, and just ... having fun. I was smiling as I looked up and around. The MANY reporters with me were smiling also. They knew the TRUTH...And yet when I saw the reporting, CNN, MSNBC and other Fake News outlets covered it as serious news & me thinking of myself as the Messiah. No more trust!"

"Is there a way we can do something like that, by injection inside or almost a cleaning?"

During a 23 April briefing, Homeland Secretary undersecretary William Bryan had reported that sun exposure and cleaning chemicals like bleach could kill the coronavirus on surfaces.

Amid the pandemic that had claimed more than 55,000 lives in the US, the president wondered aloud whether Covid-19 could be cured through "ultraviolet or just very powerful light" exposure "inside the body".

He then suggested disinfectant could be injected into a patient.

The president said: "And then I see the disinfectant, where it knocks it out in one minute. And is there a way we can do something like that, by injection inside or almost a cleaning, because you see it gets in the lungs and it does a tremendous number on the lungs, so it'd be interesting to check that, so that you're going to have to use medical doctors with, but it sounds interesting to me. So, we'll see, but the whole concept of the light, the way it kills it in one minute. That's pretty powerful."

He added: "It wouldn't be through injections, almost a cleaning and sterilization of an area. Maybe it works, maybe it doesn't work, but it certainly has a big effect if it's on a stationary object."

Cleaning companies, the Centres for Disease Control and Prevention and doctors and health officials across the US issued warnings against Americans not to ingest or inject cleaning chemicals.

White House officials had scrambled to explain the president's statement. The following morning, White House Press Secretary Kayleigh McEnany said: "President Trump has repeatedly said that Americans should consult with medical doctors regarding coronavirus treatment, a point that he emphasised again during yesterday's briefing. Leave it to the media to irresponsibly take President Trump out of context and run with negative headlines."

On Sunday, Dr Deborah Birx told reporters that the president was "spitballing" ideas.

But the president undermined both of their responses on Friday when he told reporters that he was "asking a very sarcastic question to the reporters in the room" instead.

He also claimed that he wasn't addressing Dr Birx — who sat to his right during the White House briefing on Thursday — but was speaking to a "laboratory expert". The transcript and video from the briefing show him addressing Dr Birx by name and her responding to him.

"In this case, he was being super earnest" and hoping to say something helpful, Prof Mercieca tells The Independent. "But he's not thinking about the consequences of that or knowing what the consequences are ... He can't admit he was wrong."

"When will the Noble Committee DEMAND the Prizes back, especially since they were gotten under fraud?"

In a series of furious, now-deleted Twitter messages on 26 April, the president raged at the press over coverage of his daily routine and claimed that reports of a federal probe into Russian interference in US elections have been "proven totally wrong". He said that reporters who earn a "Noble" prize (there is no such prize for journalism) should be sued, and that the prizes should be returned "to the REAL REPORTERS & JOURNALISTS who got it right."

He appeared to have mixed up Pulitzer prizes with the Nobel prize, which he spelled incorrectly four times.

The president said: "Lawsuits should be brought against all, including the Fake News Organizations, to rectify this terrible injustice. For all of the great lawyers out there, do we have any takers? When will the Noble Committee Act? Better be fast!"