In the years just before Donald Trump’s ascent, political commentary increasingly aspired to a quasi-scientific style of analysis, with data journalism in all its forms supplanting the old-fashioned emphasis on hunches, narratives and vibes.

In the Trump era, though, the mythic has had its revenge on the merely quantifiable. The data is still useful, in its place, but now even pollsters talk about their “art”, and like strange birds in the Roman Forum, the more unlikely outcomes have come home to roost.