There are so many questions which have arisen out of the US presidential election that the only way to follow them through is to follow due process which is what is mandated under the Constitution, says Sky News contributor Cory Bernardi.

"Those people who have said Trump should concede, those people have said there is no evidence of any fraud or collusion or any problem with this election at all are just mind-numbing," Mr Bernardi said.

"They've suspended any rational thought," he told Sky News host Alan Jones.

Mr Bernardi said the simple fact is "dead people are being recorded as voting," in the presidential election.

Joe Biden was declared the winner of the crucial swing state of Pennsylvania on Saturday (local time) winning the state's 20 Electoral College votes and therefore the presidency.

President-elect Joe Biden has pledged to be a president who seeks to unify the country and not see red or blue states, but the United States.

Mr Trump however is refusing to concede at this point and vows to fight for a recount in several states.

Mr Bernardi said "it's absolutely got to go to the Supreme Court".

"Ultimately, I think the next president is going to be decided by the rulings of the Supreme Court".