He always said he was a winner; winning was his brand. And on Tuesday night in New Hampshire, Donald Trump finally got to live up to his own hype.

Reality and the brand came together at last.

It was, first, a victory over his opponents. Keen to show magnanimity in triumph, Trump was quick to tell a victory party jammed with supporters how there were “some very talented people” among the rivals he had defeated — a tribute whose gracious exterior could not conceal the utter condescension within. But Trump’s victory was over much more than the trailing pack of senators and governors squabbling over the right to consider themselves Trump’s challenger — who, in that very process, only confirmed his message that he stands on a plane above mere politicians.

His was also a victory over the norms and conventions of US politics. Trump did not just tear up the rulebook in New Hampshire: he shredded it and burnt its remains.

His defiance ran to both the large and small. Conventional wisdom says that the voters of New Hampshire can only be won over one at a time, by retail politics of the most intimate kind: they won’t give you their vote unless they’ve seen you, eyeball to eyeball, ideally several times. That was the logic that informed Ohio governor John Kasich’s dogged campaign — he did more than 100 “town hall” meetings in the state — and which brought him a handsome second-place finish.

Trump was having none of it: the tiny meetings or drop-by visits to diners of New Hampshire folklore were not for him. He flew in on his private jet for big rallies in big arenas and promptly flew out again; it’s said that he did not spend a single night in the state. Such disdain is meant to be punished. But not for Trump.

Similarly, Republicans comply with a golden rule: thou shalt not cross Fox News. Trump did — and it did him in no harm at all. If anything, it won him more favourable coverage from Fox’s cable rivals. The political handbook says that you’re not meant to use vulgar language in public: such crudity looks “unpresidential”. Yet, Trump insulted one of his opponents, Senator Ted Cruz, on Monday night before a vast audience.

Disregard for political correctness

The moment guaranteed Trump yet more attention and airtime, and seemed only to make his supporters admire his disregard for “political correctness” — or what others call courtesy — all the more. Received wisdom would say that no politician can breezily promise the earth, offering no details, without being dismissed as a charlatan. But Trump’s brazenness on this score is breathtaking. “We’re going to win so much, you’re going to be so happy, we’re going to make America great again,” he told his victory party.

He speaks in a similar vein on every topic. While others might feel an obligation to sketch out something at least approaching a policy, Trump feels no such constraint. On unemployment: “I’m going to be the greatest jobs president.” On the Middle East: “We’re going to knock the hell out of [Daesh, the self-proclaimed Islamic State of Iraq and the Levant].” On drug abuse, a particularly sharp problem in New Hampshire: “We’re going to end it. It’s going to be over. We’ll get it done.”

How? Don’t even ask. He’ll surround himself with smart people — “the best” — and they’ll fix it. “Believe me.”

And the extraordinary thing is, many thousands of Americans are ready to do just that — to believe Donald Trump. To believe that he will be, as Stephen Stepanek, a Republican member of New Hampshire’s House of Representatives put it to the Guardian, “our saviour”. It’s a strong word, but it captures well the wave that Trump rode to victory in New Hampshire. It defies the usual laws of political gravity. And right now it’s not obvious who or what will stop it carrying him all the way to the White House.

— Guardian News & Media Ltd

Jonathan Freedland is the Guardian’s executive editor, opinion.