Whoever wins the White House will support Australia but the economic policies of Kamala Harris and Donald Trump both spell disaster, a former ambassador to the US says.
"It is, singularly, the worst election campaign in living memory," Joe Hockey told the National Press Club in Canberra on Thursday.
The US economy would take a substantial hit under trade tariffs implemented by either administration, which would spur price increases and likely reduce the value of the US dollar, the former Liberal treasurer said.
"It is ground zero in terms of making promises that are unfunded and probably cannot be delivered," he said.
"America now represents the greatest sovereign risk for business and for countries around the world."
Unintended consequences of tariffs or embargoes on China would have significant consequences for Australian companies.
Mr Trump's Republican inner circle was "hell-bent on big tariffs", Mr Hockey added.
He also claimed an "anti-China" draft bill set to go before the US Congress between the November 5 presidential election and the January inauguration would have a "profound impact on us", but didn't elaborate.
Still, Mr Trump's spending policy was "absurd in its largesse" and would significantly spur US inflation.
"His policies are not only inflationary but they're hugely expansionary," Mr Hockey said.
"It's like a sugar hit - it's handing a box of chocolates to a four-year-old."
But Australia was in an "incredibly good position with both candidates", he said, adding former Liberal prime ministers Malcolm Turnbull and Scott Morrison worked well with the previous Trump administration and current US ambassador Kevin Rudd was doing a good job in Washington.
"There's such enormous goodwill towards Australia, and the beauty of it is it goes down to everyday Americans," he said.
Asked who would win the presidential election in November, Mr Hockey was less clairvoyant, saying neither candidate could be written off.
Mr Trump was the most influential man in US politics in a generation, with more than a third of voting Americans saying they would vote for him regardless of whether he was a Democrat, Republican or independent, Mr Hockey said.
"You've never seen anyone with that influence," he said.
Ms Harris, the Democrat runner, was contending with elements of the US that were "both misogynistic and racist".
Mr Hockey argued that not everyone who turned out for Joe Biden in 2020 would turn up for her in November.
While Mr Trump has made "absurd" comments, including unproven and racist claims about immigrants eating cats and dogs, he had cut through.
US voters would be thinking about illegal immigration, even when Mr Trumps claims were openly mocked, and that debate favoured the Republicans, who are generally seen as better communicators on immigration and the economy.
Ms Harris, in turn, was tapping into a groundswell of people supporting the right to choose an abortion, which was an equally hot-button issue in the US, Mr Hockey said.
Mr Hockey, who served as treasurer under ex-prime minister Tony Abbott, is the co-founder of corporate advisory firm Bondi Partners.