As long as Clinton holds cards to her chest, Trump can play the innuendo game

And these days, there's a risk that all the nonsense about Clinton could become more believable because it is bookended by facts – a fainting fall in 2013 brought on by a stomach virus, in which Clinton banged her head on a toilet and, on examination, was found to have a blood clot between her skull and brain; and now, Sunday's drama which may have seriously punctured Clinton's claim to physical, as much as political, strength.

In Clinton's case the crisis of believability is enhanced precisely because as many as 60 per cent of Americans see her as untrustworthy  - so she would deny it, wouldn't she?

After a series of coughing bouts, Clinton was diagnosed with pneumonia on Friday – but instead of resting up and coming clean about a condition that affects as many as 2 million Americans a year, her campaign sat on the news and the candidate attempted to stick to her schedule – possibly contributing to the unforced error of her "basket of deplorables" attack on Trump supporters on Friday evening; and certainly contributing to all the negative reporting about her collapse on Sunday.

Clinton cancelled a planned trip to California on Monday and Tuesday and remained holed up at her home in Chappaqua, New York - but aides said she would be back on the campaign trail later in the week.

Met with a barrage of criticism from all sides in the wake of Sunday's drama, the Clinton campaign is in damage control on two fronts.

First it needs to counter the optics of Clinton as a sick candidate. And second it needs to diminish another display of near-pathological secrecy that is the Achilles heel of her campaign – telling reporters that she had simply "overheated", when the campaign knew she had pneumonia, was a lie; and her telling reporters that she "felt great" as she left her daughter's Manhattan apartment late on Sunday morning was a lie too.

In holding all the cards to her chest, Clinton is a sitting duck for Trump's cluster-bomb attacks of rhetoric and innuendo.

In challenging Clinton's credibility, it's always useful for Trump to allude to the online nonsense, prefacing his comments with "I've heard …" or "people are saying …" or as he sometimes does, to trail off with "... something's going on".

But Trump would hit a jackpot if an incident such as Clinton's hasty exit from the September 11 anniversary commemoration on Sunday could be made to stick in voter consciousness at this point of the campaign, given Clinton's faltering performance in opinion polls.

In a cutting response to Clinton's predicament, former Obama campaign strategist David Axelrod linked her health crisis to that about her emails, tweeting: "Antibiotics can take care of pneumonia. What's the cure for an unhealthy penchant for privacy that repeatedly creates unnecessary problems?"

Across the aisle, former George W. Bush strategist Matthew Dowd suggested Clinton take "a miracle drug called transparency".

Clinton communications director Jennifer Palmieri tweeted on Monday: "We could have done better yesterday, but it is a fact that public knows more about [Hillary Clinton] than any nominee in history."

And in a round of TV interviews, Clinton spokesman Brian Fallon committed to releasing more of her medical records this week, "to put to rest any lingering concerns about what we saw [on Sunday] … [and to show she has] no other undisclosed condition".

All this is a direct acknowledgement of the campaign's concern that while as many as three-quarters of registered voters don't buy into the imaginings of the conspiracy theorists, the handling of the pneumonia diagnosis has the potential to work against Clinton on two fronts – to rock voter confidence in her health and/or to further damage her historically low favourability rating with voters, on which she is now neck and neck with Trump.

Since Sunday, Trump has been uncharacteristically quiet on the issue of Clinton's health – seemingly in response to advice that having put the issue  out there endlessly, it would serve him best to simply wish her well.

But the Republican candidate did move to take advantage of any uncertainty about Clinton's health, by scheduling a Thursday appearance on the Dr Oz syndicated TV show for a tell-all on his own health – based on a physical examination he says was done last week.

And he couldn't resist one of those throw-away lines of his:  "Like you, I see what I see ... something's going on, but I just hope she gets well."

So the conspiratorial raving of an army of online nutters is daily fodder for Trump – and his surrogates. Their insidious rhetoric feeds off these wild stories that abide by a mantra of make-belief tabloid journalism – never let facts get in the way of a good story.

Producing no evidence, Trump tweets about Clinton sneaking naps – questioning her physical strength and "mental stamina". His spokeswoman Katrina Pierson is shameless in telling MSNBC that Clinton suffers dysphasia – an inability to communicate induced by brain injury; which is passing strange given all the speeches Clinton makes. The surrogates often charge that Clinton is "frail".

A photo of Clinton being guided on some steps after she slipped is offered as proof that she doesn't have the physical strength to be president.

As part of a weeklong "investigation" of Clinton's health, Fox News' Sean Hannity runs a clip of her answering a reporter's question, in which a "bizarre head-bobbing episode" is indicative of a seizure so violent that the reporter is "scared" – but Clinton is merely being animated and the reporter, Lisa Lerer of the Associated Press, says it's all baloney.

Clinton doesn't sit on a sofa as others do – because of her "secret health crisis" she has to be "propped up" by the cushions around her. She can't stand up, and so uses a "hidden stool, behind, to keep her held up". She takes weekends off "because she's exhausted". She travels with her "handler" who helps with her frequent "seizures".

Trump's key surrogate and former New York mayor Rudy Giuliani claims: "[Clinton's] got to take three days off and one day on – and seems to be sitting in a chair most of the time."

Apparently Clinton suffers "decision fatigue". Her hand gestures and a "freezing gait, dyskinesia and on-off symptomology" are "consistent with early onset of Parkinson's". She is "often confused". She laughs "inappropriately" and at times is seen with an "inappropriately exaggerated, wide-mouthed smile and extreme wide-open eyes".

A State Department email, released by WikiLeaks, that fits with Clinton's quest to have $US2 billion invested in finding a cure for Alzheimer's Disease by 2025, is offered as proof that the candidate and possibly her husband are hiding their own cases of Alzheimer's or Parkinson's – because the email is about Modafinil, a drug being used experimentally to treat both conditions.

After the onset of Clinton's coughing problem in Cleveland early last week, the Drudge Report posted a spoof picture of the reporters travelling with Clinton wearing surgical face masks.

And in the absence of facts, they get made up – fake medical documents in which Clinton's doctor Lisa Bardack purportedly diagnosed dementia were floated on Twitter last month.

Bardack has reaffirmed a 2015 letter, two pages in which she refers to the 2012 fall and its aftermath and to other easily treated conditions, hypothyroidism and seasonal allergies, while declaring Clinton to be "a healthy 67-year-old woman" who is "in excellent physical condition and fit to serve as president of the US".

Twitter went into overdrive with claims that Clinton has a double – the woman who emerged from her daughter's apartment building was not the Hillary Clinton who had been evacuated from Ground Zero a couple of hours earlier.

And because the claims about Clinton's health don't get the traction their creators demand, there are even charges that the likes of Google and Twitter are manipulating their search algorithms to suppress information.

Donna Halper, a professor of media studies at Lesley University in Massachusetts, explains to ThinkProgress.org: "What you're seeing on the right – and it's really pernicious, but it's really effective in the rightwing echo chamber – is the belief that Hillary Clinton isn't healthy.

"It's being spread by rightwing blogs; it's being spread by the National Enquirer – where it's a front-page story; it's being spread by memes; it's being spread by doctored images that Sean Hannity put out there; and by Donald Trump – 'Oh, well she doesn't have the stamina!'"

ThinkProgress traces the strategy to present Clinton as too old and sickly to be president to 2014, where it began "with political axe man [and George W. Bush strategist] Karl Rove".

"The same man who had peddled suggestions that [Bush's rival for the 2000 Republican nomination] John McCain was mentally unbalanced from his time as a prisoner of war and that [would-be 2004 Democratic nominee] Howard Dean "looked like a madman" warned of Clinton's 2012 three-day hospitalisation for a blood clot: 'Thirty days in hospital? And when she reappears she's wearing glasses that are only for people who have traumatic brain injury? We need to know what's up with that.'"

The rise of the internet, social media and the fracturing of mainstream media are critical in this process – and when the mainstream media ignores or debunks the latest wild or crazy online prognostications, it's invoked as proof that they are corrupt, manipulated and/or partisan.

Halper points to the "everyone's a producer, everyone can create content" simplicity of new age media: "Today anyone can spread a bizarre theory. You can take a meme that has something utterly false – something that the person never said – and suddenly thousands and thousands of people are retweeting it."

It follows that this kind of "content" becomes more believable the more mainstream media can be delegitimised – hence the longstanding distrust of the mainstream (or to use a Sarah Palin-ism, "lamestream") media fostered by the GOP and, more recently and relentlessly, by Trump.

"That's part of the Republican playbook: delegitimise the places where you get your facts and then, in the trust vacuum, beliefs and conspiracies can take hold … this seems to be an election where beliefs are front and centre – this is really where we started to see beliefs overcoming facts."

Oddly enough, the conspiracy theorists accept that they can go too far. On Monday WikiLeaks tweeted, but only briefly, before removing the following check-the-box poll of readers:

"Hillary Clinton's collapse … prior coughing fits & unusual facial and body movements are best explained by:

• Allergies & personality
• Parkinson's
• MS
• Head injury complications"