A few hundred local party members packed into an airport hotel conference room near Norwich in eastern England on Thursday night for the penultimate hustings event that has taken Truss and Sunak across Britain, trying to woo members.
The event ran through cherished Tory values, from patriotism and individual responsibility to scathing attacks on Labour, Scottish independence, the EU and the so-called "culture wars".
It was meat and drink to the mainly elderly audience, who were joined by younger Tories in "Ready for Rishi" or "Liz for leader" T-shirts.
Looming large, as it has increasingly done since Johnson resigned on July 7, was inflation, with rates at a 40-year high, and concern about sky-high energy bills over winter.
Sunak again pushed his proposal of more aid to the poorest while Truss was unwavering in her preference for tax cuts.
That found favour with the farmer and local councillor Julian Kirk. "Businesses are suffering with tax rates at the moment," he told AFP.
Kirk, wearing a UK-Ukraine lapel pin, said he trusted Truss to stand up to Russian President Vladimir Putin over his invasion of Ukraine.
"If we can stop him, energy prices would fall slowly," he added.
The local Tory party chairman in Norwich, Simon Jones, also backed Truss, who has represented a local constituency since 2010.
"She has done a better job than all the cabinet ministers," said Jones, 56, of the foreign secretary.
Supporters of former finance minister Sunak insist their man has proved his credentials because of his Covid support package for businesses.
"I'm not necessarily in favour of loads of handouts either but this (the cost of living crisis) is a once-in-a-generation event, just like the pandemic," said librarian Iain Frost, 37.
"I think one of the government's main duties is to protect its people," added Frost, who like Truss is a former member of the centrist Liberal Democrats.
Sunak was an early frontrunner in the leadership race But recent polling suggests Truss now has a runaway lead of more than 30 points.
"I'm surprised that Rishi Sunak isn't more popular," said retired policeman John Crane, 71.
"I think his policies are far more sensible for the problems that the country is facing at the moment."
Ian Dimmock, also 71, agreed: "There should be a huge move not towards tax cuts for us but to help the lower-paid people."
But he said he was still undecided about who to vote for, as the deadline to return ballots loomed on September 2.
Britain's next prime minister will be decided by just under 200,000 grassroots Tory members, with the result announced on September 5.
As the leader of the biggest party in parliament, the winner will become prime minister.
Removal vans have already been seen at Downing Street, while Johnson, who has stayed on as prime minister until his successor is chosen, holidayed.
His ignominious departure, after a series of scandals including lockdown parties in government, is still on everyone's mind.
Jones said he was a "strong supporter" of Johnson, who won a landslide victory in 2019 on a promise to take the country out of the European Union.
"I thought his enthusiasm was great," he said.
"What finally got to me was talking to the people on the street. We had lost the confidence of the people."
Public trust saw Johnson's Tories suffer a string of by-election defeats in formerly safe seats, and a haemorrhage of seats in local polls.
Sunak supporter Elizabeth Nockolds, 71, said she was disappointed Johnson quit as he was still popular with many people despite his many problems.
But she said of his lockdown breaches, for which he was fined by police: "I felt that if he's asking the public to do something, he should do it as well."
Some activists can't forgive Sunak for triggering Johnson's downfall by resigning.
Kirk noted that Truss "backed Boris right until the end, which is something that appeals to most of us".
The next general election is due by January 2025 at the latest but, after 12 years in power and shorn of their populist figurehead, few believe either Truss or Sunak can lead the party to victory.
"Boris Johnson could do it. Unfortunately, he's ruined his chances," said Crane.