Donald Trump’s weekend rally in Oklahoma highlighted growing vulnerabilities in his campaign, despite it being designed to show strength and enthusiasm heading into the critical final months before the presidential election.

The Oklahoma rally crystallised a divisive re-election message that largely ignores broad groups of voters – independents, suburban women and people of colour – who could play a crucial role in choosing Mr Trump or Democratic challenger Joe Biden as the next US president.

The lower-than-expected turnout at the comeback rally, in particular, left Mr Trump fuming.

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“There’s really only one strategy left for him, and that is to propel that rage and anger and try to split the society and see if he can have a tribal leadership win here,” former Trump adviser-turned-critic Anthony Scaramucci said on CNN programme Reliable Sources.

The president held his self-described campaign relaunch in Tulsa as the nation grappled with surging coronavirus infections, the worst unemployment since the Great Depression and sweeping civil unrest.

Election 2020 TrumpPresident Donald Trump supporters cheer as Trump speaks during the rally (Evan Vucci/AP)

Yet Mr Trump did not offer even a token reference to national unity in remarks that spanned more than an hour and 40 minutes.

Nor did he mention George Floyd, the African American man whose death at the hands of Minnesota police late last month sparked a national uprising over police brutality.

But he did add new fuel to the nation’s culture wars, defending Confederate statues while making racist references to the coronavirus, which originated in China and which he called “kung flu”.

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He also said Democratic politician Ilhan Omar, who came to the US as a refugee, “would like to make the government of our country just like the country from where she came, Somalia”.

Mr Trump won the presidency in 2016 with a similar tone, aimed largely at energising conservatives and white working-class men.

Election 2020 TrumpPresident Donald Trump supporters listen as Mr Trump speaks (Evan Vucci/AP)

But less than four months before early voting begins in some states, there are signs that independents and educated voters — particularly suburban women — have turned against him. Republican strategists increasingly believe that only a dramatic turnaround in the economy can revive his re-election aspirations.

“It’s bad,” said Republican operative Rick Tyler, a frequent Trump critic. “There’s literally nothing to run on. The only thing he can say is that Biden is worse.”

But the day after Mr Trump’s Tulsa rally, the president’s message was almost an afterthought as aides tried to explain away a smaller-than-expected crowd that left the president outraged.

The campaign had been betting big on Tulsa.

Mr Trump’s political team spent days proclaiming that more than one million people had requested tickets.

They also ignored health warnings from the White House coronavirus task force and Oklahoma officials, eager to host an event that would help him move past the civil rights protests and the coronavirus itself.

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His first rally in 110 days was meant to be a defiant display of political force to help energise Mr Trump’s spirits, try out some attacks on Mr Biden and serve as a powerful symbol of American’s re-opening.

Election 2020 TrumpPresident Donald Trump is said to have breated campaign officials for the poor turnout (Sue Ogrocki/AP)

Instead, the city fire marshal’s office reported a crowd of just less than 6,200 in the 19,000-seat BOK Centre, and at least six staff members who helped set up the event tested positive for the coronavirus.

The vast majority of the attendees, including Mr Trump, did not wear face masks as recommended by the Trump administration’s health experts.

After the rally, the president berated aides over the turnout. He fumed that he had been led to believe he would see huge crowds in deep-red Oklahoma, according to two White House and campaign officials who spoke on condition of anonymity.

There was no sign of an imminent staff shake-up, but members of Mr Trump’s inner circle angrily questioned how campaign manager Brad Parscale and other senior aides could so wildly over-promise and under-deliver, according to the officials.

Election 2020 TrumpPresident Donald Trump arrives on stage (Evan Vucci/AP)

Publicly, Mr Trump’s team scrambled to blame the crowd size on media coverage and protesters outside the venue, but the small crowds of pre-rally demonstrators were largely peaceful. Tulsa police reported just one arrest on Saturday afternoon.

It is unclear when Mr Trump will hold his next rally.

Mr Trump is already scheduled to make appearances on Tuesday in Arizona and Thursday in Wisconsin. Both are major general election battlegrounds.

Mr Biden’s campaign, meanwhile, reacted to the Tulsa rally by saying Mr Trump “was already in a tailspin” because of his mismanagement of the pandemic and civil rights protests.

“Donald Trump has abdicated leadership and it is no surprise that his supporters have responded by abandoning him,” Biden spokesman Andrew Bates said.