Barack Obama has always threatened to be more of a movement than a mere candidate and tonight, in the convention center in downtown Columbia where his supporters gathered to celebrate a famous victory, a movement it certainly seemed.
The overwhelmingly young – and racially mixed – crowd came together even before the polls closed, hungry for a repeat of the extraordinary night 23 long days ago when Obama won his first, breakthrough triumph in Iowa.
They had been starved of success after Hillary Clinton had won twice, in New Hampshire and Nevada. Last night they yearned to taste success once more.
So when the giant TV screens flashed up with early word of an Obama victory in what was a must-win primary for him, the crowd erupted with that most heady of cocktails: joy mixed with relief.
Then, as the TV numbers began to climb, showing that Obama had not just won but walloped his opponents – bagging twice as many votes as Clinton – they soon succumbed to euphoria.
It wasn’t just delight in Obama’s success; they were also revelling in the crushing defeat of the double-headed rival who had thrown everything at them in the course of the last week. One truly striking moment came when the giant TV screen cut to a live picture of former president Bill Clinton: the entire Obama crowd joined in throaty and spontaneous boo-ing.
That a onetime Democratic hero could get that kind of treatment from a Democratic crowd is an indication of quite how bitter this contest had become.
But of course the greatest show of emotion was for the candidate himself.
Obama arrived to a thundering response and delivered another storming speech – its impact only slightly dampened by the presence of two TelePrompTer screens.
Once again he repeated his plea for an America united. But he made two other, crucial moves. First, he subtly rejected the Clinton attempt to cast him as "the black candidate", emphasizing instead that his support was diverse, "young and old, rich and poor, black and white, Latino and Asian."
Second, and of equal importance, he worked to brand his opponents – never mentioned by name – as representative of "the status quo", a Washington mode of politics whose day is done. The effect was to say that the Clintons and George Bush were all of a piece – and they represented the past.
This contest surely has plenty more twists to come, but Obama tonight won back that precious sense of possibility that had seemed in peril after New Hampshire.
His supporters wanted to know if he could win and tonight he answered with a slogan that became a collective roar: "Yes we can."