The certification, scheduled for 13:00 on Monday, is normally a symbol of America’s commitment to the peaceful transfer of power despite partisan disagreements.

But this time, it has become an emblem of Trump’s extraordinary political comeback and his complete takeover of the Republican Party.

Trump celebrated the moment on Truth Social, writing: “Congress certifies our great election victory today – a big moment in history.”

House Speaker Mike Johnson has vowed to go ahead with the certification in spite of the weather, telling Fox News: “Whether we’re in a blizzard or not, we’re going to be in that chamber making sure this is done.”

Harris, meanwhile, has vowed to “perform my constitutional duty as Vice President to certify the results of the 2024 election.”

“This duty is a sacred obligation – one I will uphold guided by love of country, loyalty to our Constitution, and unwavering faith in the American people,” she said in a video statement.

Ordinarily there would be little need for a vice-president to declare such an intention. The US Constitution requires the certification of a presidential election on 6 January, and for the vice-president to oversee the vote.

But last time the US Congress gathered to certify the election of a US president, the vote was delayed for several hours because rioters, animated by a false belief that the 2020 election was stolen from Trump, smashed through windows, beat their way through lines of police officers, crashed the US House chamber, and ransacked the office of then-Speaker Nancy Pelosi.

In a speech in Washington DC that day, before the violence broke out, Trump told a crowd to “fight like hell” but also asked them to “peacefully” make their voices heard.

Lawmakers, including Republicans, were forced to cower in the basement and Capitol staffers hid wherever they could find shelter. Trump’s vice-president at the time, Mike Pence, was whisked into hiding as rioters erected a gallows on the Capitol grounds and called for his hanging because he refused to inaccurately certify the results in Trump’s favour.