When Donald Trump stood behind the podium at Trump Tower on 16 June last year and announced his run for presidency, the voice of one man in particular stood out.

“Trump! Trump!” the man shouted in the background. “You’re what we need!”

That voice - the voice of a man who is fed up with the political establishment - has fueled the wave of momentum upon which the New York-based real estate mogul and celebrity sailed through the primaries in March, becoming the party nominee in July.

Despite accusations of sexual assault, exposed in a resurfaced video from 2005, he still has strong support from the voter base across the rust belt and southern states, who praise his support for gun laws, anti-abortion pledges and his tough talk on Isis.

Around 120 million votes will be cast come 8 November, and political experts say at least 40 million of those votes are likely to swing Republican, whatever the nominee's policies.

What does he have to offer voters, and why is he still, in most polls, only trailing a few points behind his rival?

Below are the most important factors supporting Mr Trump, which could still see him clinch the White House:

"Benefitting" Americans via trickle-down economics

He has made money, lost money, negotiated deals and built tall skyscrapers.

As well as being the outsider, jump-starting his campaign with his own money and representing the opposite of “political correctness”, millions of Americans perceive his business “success” as power that will ultimately benefit them.

“One element going on here is a projection of power that a lot of Americans, who might be thinking about voting for him, feel anxiety about, and they have felt that way for decades,” said Sean Gailmard, a political science professor at Berkeley.

“It’s about job growth and job loss and income growth, and what the economy will do for people whose middle class fathers had jobs in manufacturing.

“Yet it is odd beyond belief that the billionaire who would sell his own mother to make a dollar would be their champion.”

Many voters' belief in trickle-down economics is also expressed via Mr Trump's current refusal to release his tax returns and his admission that he takes advantage of tax loopholes.

“Americans see success as business success, even if he’s going screw them over, people respect that," said Mr Gailmard. "Politicians have one million ways to screw you before the sun rises every day. We may as well have someone who is honest and upfront about it."

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Ripping up trade deals and negotiating "better" ones for the US

Mr Trump regularly says that NAFTA, signed by Bill Clinton, was a “disaster”. He also proposes slapping a 45% import tariff on Chinese goods and has pledged to stop American companies moving abroad.

Diana Owen, associate professor of communications, culture and technology at Georgetown University, and the author of several books on politics including American Government and Politics in the Information Age, said trade is the one issue that has really “hit home” among Trump voters.

“He doesn’t have much in the way of policy that is consistent,” she said. “But he's driving home the trade issue - whether he is right or not - by saying that Americans are losing jobs to other countries.

“Some people are working two to three jobs and are still not making it, so when he says these 'foreign countries benefit from us', the issue of trade really appeals to them.“

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Embracing Republican values

Even though he used to be a Democrat, Mr Trump has managed to adopt classic Republican stances during this campaign on tax, guns, abortion and immigration. He has also been endorsed by the likes of the Family Research Council and the National Rifle Association.

Geoffrey Skelley, associate editor of Sabato’s Crystal Ball at the centre for politics at Virgina University, said the nominee could do as well with evangelical voters as Mitt Romney or George W Bush did, as most of these voters would want him to appoint a conservative supreme court justice who was pro-life and against gay marriage.

“His voters have a level of discomfort with change, both economic and demographic, as well as changing social norms,” he said. “They are who people don’t like to have to 'press one for English' when they call a phone line, and they are displeased that gay marriage is legal nationally.”

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Peddling an anti-immigration and refugee stance

“We’ve got to build that wall, folks,” Mr Trump often tells the crowd. He repeats it often, encouraging voters to chant back: “Build that wall! Build that wall!“

“Building a wall and being anti-immigrant is also appealing for his supporters,” said Mr Skelley.

“There is a long history in the US of anti-immigration rhetoric, or going after 'the other'. We were going after the Asian immigrants in the 20th century and the Irish in the 19th century. Being anti-immigrant now against Muslims is just another example of this.”

Mr Trump has pledged to tighten border security, carry out “extreme vetting” on Muslim and Syrian refugees, and also stop illegal immigration - without offering many concrete specifics.

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Offering something different

Mr Trump was known as a businessman and a celebrity, appearing as host of The Apprentice and the owner of Miss Universe beauty pageants.

He appeared on hit shows like Sex and the City, and offered his view on everything from the Central Park murder in 1989 to the attacks on 9/11. As a result, he had massive name recognition.

As the Republican nominee breaks away from the traditional image of a politician, he also offers a "beacon of hope" for uneducated voters and provokes nostalgia among older voters.

His slogan, "Make America Great Again", suggests that America was once great and it now is not, said Mr Skelley.

"It reflects voters’ concerns about their future and economic place in this country," he said.

His "different" approach also helped his success during the primaries.

"He stood out among the field of candidates in the primaries, who were not distinctive with overlapping bases. Ted Cruz, Marco Rubio and others were going for the same type of voter," said Ms Owen of Georgetown University.