Those who initially saw the Trump candidacy as an exercise in buffoonery and exhibitionism, and gradually accepted it as an insurgency, now see it as an attempt to hijack and ravish the Republican Party and even to hoodwink the entire electorate. The alternative interpretation has been that Donald Trump, though a billionaire, had the genius of expressing public grievances in an Archie Bunker style that mocked political correctness and was popularly seen as plain talk from the only candidate not in any way complicit in the terrible blunders of America’s political class since the end of the Cold War.

Mr. Trump was also a successful businessman and impresario, not, in fact, a blue-collar clock-puncher, though he talked like one. No one can deny that Mr. Trump saw an opportunity and disclosed the existence of a massive voting bloc that all the experts, led by the Bush-Clinton joint incumbency that held great offices for eight straight terms (1981–2013), missed altogether.