Donald Trump 2.0: The 'street fighter' Trump thinks can make him President

He says the Clintons are "trailer trash", "grifters" and he wants to take them down.

He thinks George Clooney is a "moron" and a "hypocrite" for his political leanings, and he reckons Donald Trump will win the presidency in "a landslide".

He's got a wild shock of hair, a mouth that runs a mile a minute, leans far to the right, and has been described a "street fighter" and "the most dangerous man in American politics".

Welcome to Trump 2.0.

His name is Steve Bannon, and he's the new man in charge of the Don's political campaign.

Trump's appointment of his long-time supporter - Bannon is the executive chairman of the politically conservative Breitbart news site - as his campaign CEO is a sign that with 82 days of the presidential race to go, nothing is off limits.

Trump has lost support and alienated voters in droves in a fortnight which saw him insult the Khans (the Muslim parents of slain American Muslim soldier Humayun Khan); call Hillary Clinton "the devil"; say it was "very sad" that women at Fox News were "complaining" about being sexually harassed; and appear to joke about being given a Purple Heart by a war veteran.

Advised to moderate himself, moderate some of the many fights he's picked, and tone down his tough demeanour as his campaign hits rock bottom, Trump has done the opposite.

"I am who I am. It's me. I don't want to change. Everyone talks about, 'oh well you're going to pivot.' ... I don't want to pivot. I mean, you have to be you. If you start pivoting,

Certainly Bannon appears the antithesis of a man appointed to moderate the Don.

His Breitbart site has been an unashamed supporter of Trump's campaign and a Hillary Clinton attack dog. Last month, Breitbart.com even started selling limited edition "Breitbart Border Wall Construction Co" T-shirts is support of Trump's plan to build a wall on the Mexican border.

Bannon, a former naval officer, investment banker, filmmaker, and entrepreneur, has been described as a "street fighter" whose style is to "win at all costs" by former Trump campaign manager Corey Lewandowski.

Bannon has never run a political campaign. But he has made conservative documentaries, raised money for Breitbart News and hosted a Breitbart-branded radio show. Last year Bloomberg Businessweek dubbed him "the most dangerous political operative in America".

Earlier this year, when Lewandowski was accused of assaulting Breitbart reporter Michelle Fields after a Trump press conference, Fields said Breitbart executives did not do enough to support her, CNN reports.

She suggested that they sought to protect Lewandowski and Trump, and resigned, with editor-at-large Ben Shapiro and two other staffers also leaving in protest.

Shapiro said at the time that Bannon was a "bully" who "has shaped the company into Trump's personal Pravda."

He reacted to Bannon's hiring by tweeting, "I believe Breitbart became Trump Pravda so that Steve Bannon could be the conductor on the Trump Train. It was that simple."

Breitbart News is the same website that highly controversial "troll" - now banned from Twitter - Milo Yiannopoulos writes for. Yiannopoulos has a huge and devoted online following and refers to Donald Trump as "Daddy".

The Breitbart website's hiring section says it's looking for media junkies willing to "walk toward the fire" - an apt description of Bannon himself.

Keith Appell, a political consultant whom Bannon hired to promote a movie he'd made about Sarah Palin, describes Bannon as a hard-driving perfectionist with both strong organisational skills and a filmmaker's gift for storytelling.

"He gets the need to personalise and humanise what Trump wants to do," Appell said.

Bannon is also the man behind the documentary Clinton Cash, a controversial film based on the best-selling book by Peter Schweizer, investigating the Clintons' finances.

When the doco aired at Cannes Film Festival in May, Bannon unequivocally told news.com.au

Trump would win the presidency "in a landslide".

"What I find shocking is that there's this thought process that Hillary Clinton is going to be president of the United States, and to even think of Donald Trump is a joke," Bannon said.

"Trump is a product of a seething populism and nationalism that is the driving political force.

"We were the first guys to give Trump an interview three years ago in May of 2013. The mainstream just laughed at him but I'm a filmmaker and I watch the audience. They were leaning into what Trump said when he talked about making America great again, getting jobs back and stopping immigration.

"George Clooney, who is a moron, came here to Cannes and gave a press conference saying, 'Under no circumstances will Trump ever be president. Hillary Clinton will be the next president.' Well, we can't wait to make George Clooney eat his words."