That the US should have elected as president someone like Donald Trump came as a shock. But the US is a strange country, given to periodic outbursts of political madness — though perhaps never quite as mad as this. That the Dutch, often caricatured as pragmatic, bourgeois, phlegmatic, business-minded, tolerant and perhaps a little boring, might in March pick a party led by a vulgar rabble-rouser with dyed blond hair to be the biggest in the land is more surprising.