Trump as President would have the right to appoint judges and reject trade deals, including the Trans-Pacific Partnership, which the Turnbull government strongly supports.
The Obama administration had hoped the deal might be ratified by the current Congress, which can meet and pass laws before new members are sworn in. Orthodox Republican policy favours free trade and the new president won’t take office until January 20.
“Given he has been elected on this platform, it is very hard for Congressional Republicans to pass the TPP,” said Sam Roggeveen, a senior fellow at the Lowy Institute, a foreign policy think tank.
The trade deal covers one quarter of global trade and has been agreed by the governments of Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, Peru, New Zealand, Singapore and Vietnam.
If enacted, Donald Trump’s policies would have profound implications for the structure of the US government, global trade and international security.
Mr Trump has vowed to cut taxes and government spending, simplify the taxation system, raise the minimum wage and impose trade tariffs.
He wants tougher military action against Islamic State, state-directed torture, surveillance of mosques in the US, restrictions on Muslim immigration and a wall with Mexico.
The US political system may make it difficult for a president Trump to implement many of his policies. Apart from ordering military action, US presidents need the consent of Congress for most big policies.
Even though the Senate looks likely to be controlled by the Republican Party, Congress is notoriously difficult for any White House to manage. It has proven to be effective at resisting pressure to reduce government spending, one of Mr Trump’s priorities.
Mr Trump wants to repeal one of President Obama’s signature policies, medical insurance for the low-paid. What he would replace it with is unclear. He has said that “everybody’s got to be covered”.
“There will certainly be rollbacks of Obamacare and there will be conservative nominees to the Supreme Court, where there is already one vacancy,” La Trobe University professor Dennis Altman, a US politics specialist, said.
Some of Mr Trump’s most dramatic policies cover national security. He has repeatedly expressed hostility towards Muslims, and at one point suggested keeping a database on all American Muslims, although he has retreated from that.
After a terrorist attack in San Bernardino, California, he called for “a total and complete shutdown of Muslims entering the United States until our country’s representatives can figure out what is going on”.
After the proposal triggered global outrage, he promised to introduce “extreme vetting” for anyone wishing to immigrate to the US.
Mr Trump argues the US should use waterboarding and other tough interrogation methods in the fight against Islamic State.
He wants to escalate the US military campaign against IS, which already involves Australian forces, and has said he wants to “bomb the hell” out of the organisation.
But that doesn’t necessarily mean a president Trump would seek to expand US power abroad.
Experts see him as part of the “realist” school of foreign policy, which holds that powers act out of self interest rather than values. If an accurate assessment, that would make Mr Trump less likely to try to fix failed states, they say.
“He is very much a sceptic when it comes to America being the world’s policeman,” Mr Roggeveen said. “His instincts are less interventionist than Hillary Clinton.”