Donald Trump's election as US president would trigger a collapse in support for Australia's alliance with the United States, according to a new poll.
Forty-five per cent of voters believe Australia should distance itself from the United States if it elects a president like Donald Trump, compared to 51 per cent who say the alliance should remain strong regardless. 
"It's a striking and somewhat disturbing result because one of the strongest and most consistent polling results in the Lowy Institute's history has been support for the US alliance," executive director Michael Fullilove said.
In 2015, 80 per cent of Australian adults said the relationship was very or fairly important. 
Respondents were not asked their specific thoughts on Mr Trump but Mr Fullilove noted the billionaire property developer and TV personality's penchant for "outrageous and appalling" remarks.
"Donald Trump is crass and bombastic and egotistical and he embodies very few of the greatest qualities of the US: open-mindedness, generosity, willingness to lead and take a liberal definition of America's interests."
The former Apprentice host has shocked foreign policy observers with his positions on isolating the US from international obligations and alliances, empowering Asian countries to attain nuclear weapons and forcing Mexico to pay for a wall on their shared border.
Kim Beazley, the former Australian ambassador to the US, has described Mr Trump as an extreme and unrepresentative figure with "no regard for alliances at all".
Some of Mr Trump's closest advisers have assured Mr Beazley's replacement, Joe Hockey, that the candidate views the Australian alliance as a "special relationship".
Apart from close cultural and economic ties, Australia and the US have an intimate military and intelligence relationship, including the stationing of up to 2500 soldiers in Darwin and the secretive Pine Gap facility near Alice Springs. The two countries have fought together in every major military conflict of the last century.
Support for the relationship is linked to the popularity of US foreign policy and the identity of the president.
George W. Bush's presidency marked a low-point in 2007, when only 36 per cent saw the alliance as very important.
Mr Trump continues to strengthen his grip on the race for the Republican nomination but Democratic frontrunner Hillary Clinton remains favourite to win the general election in   November.
So far, polling of the probable match-up shows emphatic victories for the Democrat but Mr Fullilove said Mr Trump as president is a possibility Australia must start considering.
"He is a clear favourite to win the nomination of one of the world's great political parties," Mr Fullilove said.
"If he were to win the nomination, I think Hillary Clinton would be the favourite to win the election but either horse can win in a two-horse race."
While many Australian politicians have refrained from commenting on the state of American politics, Industry Minister Christopher Pyne recently labelled the Trump phenomenon "terrifying" and "kind of weird".
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