Trump card: We profile the US Republican candidate
He's the ultimate Washington outsider: too rich for the establishment to buy off, with a virulent hatred of all things 'liberal'. The smart money says he will crash and burn any day soon. So why has the prospect of Donald Trump in the White House never been closer?
The oddest thing about Donald Trump's relentless topping of the polls in the campaign to be the Republican candidate in next year's presidential election is the fact that he has so little in common with the people who are his most fervent supporters.
They are, generally, middle-aged and older, struggling to make ends meet; working-class, poorly educated, white and angry - angry about almost everything it would seem. He, on the other hand, is a multi-billionaire who doesn't have a back-story of early poverty, or struggle.
In fairness, neither Mitt Romney (who stood against Barack Obama in 2012), nor John McCain (2008) had much in common with those Republican supporters, either.
Yet, unlike them, Trump - who is considerably wealthier and not even a war hero - clearly connects. He speaks their language.
That it is incoherent, simplistic, inconsistent and mostly off-the-top-of-his-head language seems to be neither here nor there. They don't have to understand it. They don't need to understand it: because so unscripted and uncensored is it that they believe he isn't talking down to them.
He is, of course, talking down to them, because all he is doing is confirming their assorted fears and prejudices and throwing down rants to them, rather than reasoned responses.
And, yet, they should hate him. He was once a Democrat and used to be pro-choice: but now he's a Republican and he's pro-life. He used to be strongly anti-intervention - "We don't need our boots and our bombs on foreign soil" - but now he favours "bombing the hell out of Islamic State in every country they lurk and going after any potential enemy without asking the permission of the countries involved".
For a while, he had reservations about America's gun laws, describing them as "too loose". Nowadays, he's much more pro-gun lobby: "Some of those folks that were just slaughtered in Paris, if a couple of guns were in that room and were held by the good guys, you would have had a completely different story". At other periods he was a member of the Reform Party and a registered Independent.
In other words, he's precisely the sort of "flip-flopper" that his present supporters are used to despising. But he doesn't care. He doesn't have to care.
For what Donald Trump is trying to do is buy the White House with his own money. And that means that he doesn't have to care about the views of the Republican power-brokers, or money men; he doesn't have to care about pandering to lobbies in exchange for campaign funds; he doesn't even have to care about endorsements from so-called Republican icons, because he regards them as losers, or, worse, as "closet liberals", who sell out when they win elections.
And the campaign rules for candidates are so vague that the Republican hierarchy can't actually ditch him as a runner; they need the voters to do that for him in the Primary election process, which begins in February.
But is that what those voters will do when the primary season kicks off? He was supposed to have run out of credibility and steam at this point, but he remains comfortably ahead in just about every opinion poll. To be honest, the Republican fixers didn't mind too much at the outset, because he was generating huge media and public interest in the campaign and they hoped that, after he had been forced out of the race by centre ground grassroots, that interest would have transferred to someone like Jeb Bush.
Yet it's Bush and others who have failed to make an impact, or attract an audience. Trump is still there. Still dominating the headlines. Still defying all the predictions about his imminent collapse. Still looking like he will be the last one standing in the summer of 2016, leaving the Republicans with no choice but to endorse him as their champion to defeat Hilary Clinton - who is probably rubbing her hands at the prospect. As one Democrat said: "The only person more unpopular than Hilary is Donald."
Which brings us back to the same questions: how and why? In an age in which popular and social media is dominated by celebrity, reality TV and naked self-aggrandisement and self-belief, Trump is the perfect candidate. This is a man who lives in Trump Tower, after all, and all of whose business enterprises are named after him.
He often refers to himself in the third person and spends an awful lot of time in his speeches reminding people just how wealthy and well known he is: "Go anywhere in the world and people will know who Donald Trump is".
Yet, while they may know the name - in much the same way that they will know Disney and Coca Cola - and know that he was the star of The Apprentice for 14 seasons (the format was pioneered in America), it's hard to know what else they know about him.
He isn't particularly good when it comes to details and specifics and it's hard to avoid the conclusion that the bizarre views and controversial outbursts are just his way of hiding the fact that he doesn't really have a policy platform.
He will get a headline with something like, "How many illegal Mexican immigrants do you see on the other side of the Great Wall of China", but it won't be followed with a policy, let alone a nailed-down plan. Indeed, since he declared his presidential bid in June he hasn't even bothered with a policy platform.
His key supporters don't mind. He's appealing directly to the "I'm as mad as hell and I'm not taking any more of this" non-voting Republicans - the sort of people who believe that President Obama is a Muslim and that the presenters of Fox News should have their own section on Mount Rushmore.
He can already count on the Tea Party lobby and the broad Right wing: and if he gets the nomination he can be pretty sure that mainstream Republicans - who despise Clinton - will grit their teeth and vote for him.
But what he really needs are what are sometimes referred to as "the millions of crazies" - people who detest the political mainstream and assume that Republican presidents will turn native and morph into liberals. His pitch to them is, basically: "I don't need anybody else's funding, so I can't be bought and I won't go soft".
Trump has made the early stages of the election fun, albeit for all of the wrong reasons. This campaign has been about him and nobody else.
And if America really does want a President who is wealthier than the party political establishment at the heart of Washington and who genuinely doesn't seem to give a damn about consensus and political correctness, then Trump is their man. A self-made man who clearly worships his creator.
But I'm not convinced that's who they really want. I'm pretty sure they also want thought-through responses and nuance to back up the more colourful aspects of his character. For, when all is said and done, Trump isn't much more than a salesman who specialises in selling his own products and his own personality.
An admired quality, particularly in America, but not enough to provide a platform for one of the most powerful and influential political jobs in the world.
The smart money remains on him crashing and burning sometime soon: but the smart money has been crucially and embarrassingly wrong a number of times - and across the world, too - in the past couple of years.
Anything remains possible at this stage. Unlikely, yes, but the prospect of Trump in the White House isn't dismissed as easily and quickly now as it was six months ago.
A life so far
He was born in New York on June 14, 1946
His father, Fred, was a very successful real estate developer in New York
His mother was from Scotland and his grandparents were German immigrants
He has been married three times and has five children
He is worth around $4.5bn
He lives in Trump Tower, Manhattan