A full four years before the vote, at a time of unprecedented political volatility, only a fool would make a prediction for the next Holyrood election. So here goes: the next first minister of Scotland will be Kezia Dugdale.

My prediction is part psephology, part extrapolation, part hunch. It is also based on three beliefs. One, that the slide in SNP popularity still has some way to go. Two, that there is a ceiling of support for Ruth Davidson’s Scottish Conservatives. And three, that there is a chunk of the SNP vote that is still vulnerable to Jeremy Corbyn’s old-school socialism.

Let’s take these one at a time. The reasons for the SNP’s decline are now pretty clear. A wariness among some Nationalists about the