At this stage in the last electoral cycle, Donald Trump was being dismissed as a joke. He had entered the Republican primaries in June 2015, and had taken a lead in the opinion polls by mid-July. But almost every pundit was still writing him off as an oaf – loud, obnoxious and utterly unelectable. Like previous celebrity newcomers, he would strut and fret his hour, but there was (all right-minded people agreed) no chance at all that he would win the primaries, let alone the presidency.

Four years on, those assumptions have been turned on their heads. Now, most commentators take it for granted that Trump will be re-elected. With a booming economy and an opposition that seems simultaneously weak, woke and wacky, he is regarded as a shoe-in.

The change in tone reflects the way in which Trump has turned American politics inside out. The Republican Party has been refashioned into an altogether more protectionist, nativist and isolationist movement. Conservative commentators who, only a couple of years ago, were denouncing Trump as an interloper who had come late and malevolently to their side are now cheering him as he expands the powers of the presidency and the size of the federal government.

Oddly, though, Trump’s 2016 win was something of a fluke. When commentators are caught off guard – as they had been by the Brexit vote a few months earlier – they tend to grope around for vast and satisfying explanations, proportionate to their sense of surprise. Thus, the Trump victory was followed by a thousand op-eds that roughly said “I didn’t see this coming, but now let me tell you why it happened”. We were treated to pages of analysis about left-behind voters and culture wars and angry ex-miners in the rust belt and stump-toothed Appalachian mountain-men and blah blah.

What all this analysis missed was that Trump’s support had been, by any normal definition, low. He won fewer votes than either John McCain or Mitt Romney. He won fewer votes, come to that, than Hillary Clinton. He was outpolled on the day by most of the Republican congressional and gubernatorial candidates with whom he shared a ticket – the vast majority of whom had been standing on traditional small-government platforms.