It's so unlikely you have to pinch yourself to believe it. Donald Trump, a property billionaire and reality TV star with no political experience, loud, vulgar and with a preposterous hairstyle, is well on his way to becoming the Republican party's presidential candidate.
He's storming into Super Tuesday, when 11 US states vote in primaries or similar contests, as the frontrunner, with three successive victories. In Nevada, he got more support from Republicans than his two key challengers, Ted Cruz and Marco Rubio, combined.
The ruder he is, the more his support base rally to his standard - the less he sounds like a conventional politician, the more he is championed as the man who will punch the Washington political establishment on the nose.
He described Mexicans as rapists and wants to build a wall across that vast southern border to keep out illegal migrants - yet in Nevada, Latinos too plumped for him. He suggested that a woman TV anchor was tough on him because she was menstruating - but women remain the bedrock of his support.
Donald Trump is the epitome of the "anti-politics" politician, the man who offers authenticity over political artifice. That shorthand is too simple, of course. Trump is proving himself to be a very effective communicator and campaigner - far from turning his back on the political system, he is playing it better than anyone else around. And he has that key ingredient which really helps in American politics - almost boundless personal wealth.
And it's not just Trump who represents the rise of the insurgent candidate and the outsider politician. Bernie Sanders - a self-declared socialist in a political landscape where even "liberal" is a dirty word - has deeply unsettled the Democratic party power brokers. He's up against Hillary Clinton, a much more formidable opponent than Trump's rivals, and so far has held his own.
At 74, he's getting on a bit - but the young, those impatient for change, are his most fervent supporters.
A 20-year-old Sanders supporter, a woman, explained to me the other day why she isn't out there campaigning for the first woman to have a serious chance of being elected to the White House. "Hilary wants power for its own sake - she doesn't know what she wants to do with it," she said. "But Bernie, he wants power to change America."
Across the Atlantic, there's a lot of scoffing at the absurdity of American politics. But in Britain as well, the standalone outsider is making the political weather across parties.
Take the Mayor of London, Boris Johnson - superficially, his only point of similarity with Trump is a non-conventional haircut. He's from a well-connected family, educated at Eton and Oxford, and is a politician to his fingertips. But he has managed to create the aura of being an anti-machine politician, with his bloke-ish irreverence - the common man's common sense Conservative. It's a political conjuring act, but it's worked.
Johnson has now spectacularly broken ranks with his own Prime Minister and is campaigning for Britain to leave the European Union - there's a referendum being held in June.
And the Labour opposition has in 66-year-old Jeremy Corbyn a British version of Bernie Sanders - a habitual left-wing rebel who has challenged conventional wisdom by being elected party leader.
In both Britain and the US, the rise of these political outliers is in part about the long years of economic difficulty which has jolted the confidence of the middle-class and upset traditional political loyalties.
The aftermath of the Iraq war - and now Syria's civil war, the rise of Islamic State and the huge flow of refugees - has provoked a sense of insecurity. That encourages support for politicians who appear to have answers rather than simply restating the problem.
And where a political wave would once have taken years to build, now social media can amplify a trend, provide a virtual sense of political community, and propel new figures and movements to centrestage in a matter of weeks.
The world's biggest democracy has not been immune from this global trend towards anti-establishment politics. The spectacular rise of the Aam Admi Party is one of the most emphatic aspects of this global phenomenon of insurgent populism.
So too is the success of Narendra Modi, who presented himself as the small town outsider, at a distance from Delhi and its tarnished institutions, and used new forms of campaigning - holograms, selfies, social media - to enthuse those previously not greatly engaged with the political process.
It would be foolish to stretch the analogy between Donald Trump and Narendra Modi too far. And there is one striking difference. Unlike Trump (or indeed Sanders, Johnson, Corbyn and the other outsider political aspirants), Mr Modi isn't just campaigning for the top job - he's got it.
(Andrew Whitehead, a former BBC Delhi correspondent, is an honorary professor at the University of Nottingham and at Queen Mary, University of London.)