Hillary Clinton made a terrible mistake on Friday night.

Speaking to a star-studded audience at a fund-raiser in New York, she inexplicably decided to abuse, denigrate and mock tens of millions of her fellow Americans.

‘You could put half of Trump’s supporters into what I call the basket of deplorables,’ she sneered. ‘Right? The racist, sexist, homophobic, xenophobic, Islamophobic – you name it.’

The well-heeled, affluent, liberal, metropolitan elite crowd at super-fancy Cipriani restaurant in Wall Street, where Barbra Streisand and Rufus Wainwright performed that same night, whooped and hollered.

Friday night Hillary Clinton decided to abuse, denigrate and mock millions of Americans. ‘You could put half of Trump’s supporters into what I call the basket of deplorables,’ she sneered

I didn’t. Like many, I just winced when I saw it.

It was an astonishingly crass thing to say.

Far worse, I would suggest, than Mitt Romney’s infamous 47% gaffe during the last election campaign, when he suggested half the country were entitled victims.

Why? Because Hillary was directly, unequivocally, accusing vast swathes of Americans of being racist, sexist, gay-and-Muslim haters.

Donald Trump is currently polling around 40% (just a couple of points behind Hillary).

So that’s 20% of the entire voting nation she was tarring with her poisonous bigotry brush.

By Saturday morning, Hillary was backtracking, having realised her hideous error.

‘Last night I was grossly generalistic,’ she admitted. I regret saying “half”, that was wrong.’

The damage, though, was already done.

The fancy liberal crowd at Cipriani, pictured, loved it - but she realized her mistake and backtracked Saturday morning after Trump rightly seized onto her remarks

Her rival, as you’d expect, pounced like a ravenous hyena scavenging on a freshly slain gazelle.

‘Wow, Hillary Clinton was SO INSULTING to my supporters,’ Trump tweeted, ‘millions of amazing, hard-working people.’

His running mate Mike Pence joined in the attack: ‘The people who support Donald Trump’s campaign are hard-working Americans,’ he said. ‘Let me just say from the bottom of my heart: Hillary, they are not a basket of anything, they are Americans and they deserve your respect.’

Ouch.

Who could argue though? Trump and Pence were both absolutely right.

This WAS a very offensive and unwarranted slur against many millions of hard-working Americans.

To make things even worse, it was made right in the heart of New York’s financial establishment, to a bunch of smirking, cheering Wall Street bankers and their like.

The very people, in fact, who Hillary’s critics claim have held an iron grip on her for decades and from whom she has taken a fortune in fat speaking fees.

So this was a very, very bad mistake.

One that on its own could prove devastating to her chances of winning the election in November.

The big question is why she made it?

How could someone so smart, so savvy, so wary of making dumb public statements, utter such wildly condescending words?

Well now we know the answer.

Hillary was sick.

Very sick.

But we only know because she collapsed at the 9/11 commemoration at Ground Zero on Sunday.

We only found out Hillary Clinton was sick after shocking video of her collapsing on Sunday emerged on Twitter and her camp was forced to admit she had been diagnosed with pneumonia. Here she's being manually put into her fan after she was unable to stand

Her camp were forced to admit she had been diagnosed with pneumonia on Friday, after spending the week coughing and spluttering her way through speeches and rallies.

Pneumonia is not a trivial matter. In the United States alone, one million people seek hospital care for it every year and of those about 50,000 die of the disease.

Most people who get it are prescribed several weeks of bed rest to recover from high fevers and poor breathing.

The very last thing you should do if infected is continue with an unbelievably stressful and exhausting election campaign schedule, especially if you’re 68 years old.

Hillary, like Trump, is no spring chicken – they are two of the oldest presidential candidates in history - and has suffered from a variety of ailments reasonably common in a woman of her age.

But she is running for president, and her health is thus now a matter of massive national importance.

As her own husband, former president Bill Clinton, said in 1996: ‘The public has a right to know the condition of the president’s health.’

Rumors about Hillary’s poor health have been swarming for months, supermarket tabloids even gleefully, and ludicrously, screaming she’s on death’s door.

I was inclined to ignore them all until I watched the video of her collapse yesterday outside the 9/11 memorial service in New York.

It was genuinely shocking. This wasn’t just a fall, or an accidental tumble from someone a bit dizzy on their feet.

This was someone looking completely out of it, being propped up by her aides and then actually collapsing.

What caused it?

‘Over-heating,’ her aides said initially, after nearly two hours of deeply suspicious radio silence.

Manhattan, they briefed, was 'very hot' that morning (warm, in fact, it was around 80 degrees) and humid (although by New York City summer standards yesterday was pretty fresh).

Mrs Clinton, they assured the world, had simply ‘over-heated’.

Only she hadn’t.

In deliberately lying to downplay Clinton's health, her camp gave Trump, seen here Sunday, the second big gift of the weekend

That was a deliberate falsehood designed to downplay her condition.

Just as it was when they had blamed her coughing fit earlier in the week on ‘allergies’.

Hours more later they finally admitted that Mrs Clinton was in fact suffering from pneumonia, which her aides had all known since Friday.

Why lie?

Why not just be honest?

Hillary’s fork-tongued response to this medical episode is one of the main reasons she is not storming to inevitably victory in this race as many assumed she would.

She seems to find it impossible to just be straight with the American people.

Everything has to be spun, twisted, ‘made better’.

Protection of Brand Hillary supersedes the truth time and again, whether it’s Benghazi and her emails, or now her health.

If she’d just said she had pneumonia on Friday and gone to bed, it would have made a few headlines but everyone would have moved on from it pretty quickly. Politicians get sick like the rest of us.

Instead, she staggered onto a fund-raiser where she dropped her worst gaffe of the campaign. Who knows what effect her illness had her on thought process that night?

Why are they twisting and obfuscating everything? If she’d just said she had pneumonia on Friday and gone to bed, it would have made a few headlines but everyone would have moved on. But the combination of these events has conspired to make this Hillary’s weekend from hell

Then she hauled herself to the 9/11 memorial service and promptly passed out – sparking a torrent of negative media coverage.

The combination of these two disastrous events has conspired to make this Hillary’s weekend from hell and leaves us with two questions.

Can she recover?

And is she now telling us the truth?

Medically, of course she can recover. . .

IF she now gets the rest she should have had last week when she first got diagnosed. Cancelling her 2-day trip to California is a sign she may finally realise that trying to plough on with campaigning will only make her sicker.

And IF she really does only have pneumonia and not something even worse – a question her obfuscation on the matter sadly makes it necessary to ponder.

She has already admitted she cannot recall key details of the email scandal because of a 'concussion'.

But whether she can recover politically is another matter.

Hillary’s handed Trump two gigantic gifts in the past 72 hours.

First, she smeared millions of Americans in a vile, inexcusable and very elitist way - proving that a candidate's physical fitness can affect their judgment.

Second, she lied about her health and collapsed on camera.

Both of these things will hurt her badly with an already deeply distrusting electorate.