Does America's 2024 election come down to a choice between two different shades of your crazy uncle, one semi-senile, the other vulgar and erratic? A decade ago, when Donald Trump launched his presidential bid, there was a real clash of visions for the US at stake. "Make America great again" (Maga) heralded the end of globalisation and the return of tariffs, hard borders and nationalism: the stuff of the Dark Ages, as far as establishments on both sides of the Atlantic were concerned.