Trump's positive Covid test was a surprise that many saw coming

It is likely to go down as the biggest “October surprise” in the history of US presidential elections. Yet anyone who was paying attention could have seen it coming.

Donald Trump tested positive for the coronavirus after claiming “it will disappear”, telling the journalist Bob Woodward he was downplaying it deliberately, failing to develop a national testing strategy, refusing to wear a face mask for months, floating the idea of injecting patients with bleach, insisting to one of his many crowded campaign rallies that “it affects virtually nobody” and, at Tuesday’s debate, mocking his rival Joe Biden: “He could be speaking 200 feet away and he shows up with the biggest mask I’ve ever seen.”

It suggested a sense of invincibility even as more than 200,000 Americans died. But now chickens have come home to roost, just as they did for the similarly cavalier British prime minister, Boris Johnson, and Brazilian president, Jair Bolsonaro. Covid-19, described as the “invisible enemy” by Trump, has penetrated the Oval Office.

Related: Donald Trump tests positive for coronavirus and goes into quarantine – live updates

Thirty-two days before an election often described as the most important in living memory, this changes everything. Trump has been doing what he loves most, holding campaign rallies, on a hectic schedule in recent weeks, trying to recreate the perceived magic of 2016. Any more rallies, or flights on Air Force One for that matter, are now unthinkable under quarantine. If Trump loses the election, perhaps he will never hold a rally again.

A huge question mark also lingers over the second presidential debate scheduled for 15 October. Perhaps Trump, if he is well enough, could take part virtually. Perhaps, after what happened on Tuesday, no debate would be a mercy for everyone.

Politically, how will this play? If Trump is asymptomatic, there is a danger that he could yet again seek to minimise the virus, making a case to his supporters: what’s all the fuss about? But if he becomes seriously ill, perhaps he could benefit from a surge of public sympathy, just as Johnson did.

Dr Vin Gupta, a pulmonologist and medical contributor to MSNBC, told the network: “The presidential race has been fundamentally altered tonight. There should be no more in-person gatherings for the remainder of this season and I think there’s concern here, if the president remains asymptomatic, that he may use it to tamp down the seriousness of the infection.”

He added: “They’ve been mocking masks in some cases. The fact that this even occurred is a damning indictment and, unfortunately, kind of a ‘we told you so reality’ based on their months and months of misrepresenting good public health practice. This was avoidable.

“This did not have to happen if they were practicing the proper procedures and not going to these rallies and having these chaotic events where, of course, airborne exposure was going to happen, even if it was an outdoor setting, No masking, no distancing, what did they expect was going to happen?”

The revelation that Trump and his wife, Melania, tested positive also raised concerns over Biden, who shared a debate stage with him on Tuesday, though they did not shake hands. Many in Trump’s entourage did not wear masks in the auditorium. Trump’s senior aide Hope Hicks – who has also tested positive – was present. Considering all their travels, it is a contact tracing nightmare.

But Trump’s critics will have to be careful to avoid certain tripwires. Any sense of glee, or wishing ill on Trump and his wife will be seized on by Republicans as a sign of callousness and political opportunism.

Miles Taylor, a former chief of staff at the Department of Homeland Security and now a Trump critic, tweeted: “We should ALL wish for our President & First Lady to recover. But this is also a serious national security concern – and an alarming upshot of the White House’s lax approach to this deadly pandemic.”

Aged 74 and overweight, Trump is in the high risk category. The White House physician said on Friday that he is well enough to continue his duties. Even so, Covid-19 poses the biggest risk to the health of an American president since the shooting of Ronald Reagan outside a Washington hotel nearly four decades ago.

Should Trump’s become seriously ill and unable to function, the vice-president, Mike Pence, would take over, following the procedures set out in the 25th amendment of the US constitution. But if Pence falls sick as well – it is unclear whether his Covid-19 status is known – a constitutional crisis looms.

Under the rules of 1947 Presidential Succession Act, the presidency should pass to Nancy Pelosi, the House Speaker. But that would mean a switch from Republican to Democrat. The Washington Post noted earlier this year: “Any effort to transfer power from Trump and Pence to Pelosi would surely inspire legal and political challenges, adding to chaos at precisely the moment the nation desperately needed stability.”

As president, Trump had a duty to keep Americans safe. In the end, he could not keep himself safe. As one infamously said, it is what it is.