If we do the maths, the target readership for this teen adaptation of Jacinda Ardern’s bestselling memoir A Different Kind of Power were at primary school when she was prime minister. Those were the days when Ardern’s “stardust” – as her particular brand of political magic was described – saw her reach extraordinary heights of popularity, both at home and abroad. But, as we know from the adult edition of her memoir, Ardern had always struggled w…