It was four weeks before election day when I spoke to one member of the constituency Labour party in Holborn and St Pancras, in central London, as he was on his way out of the door to go canvassing in Barnet, several miles away in north London. This is not at all unusual: victory is assured in Keir Starmer’s constituency, which has been continuously red since its creation in 1983. Next door, in Islington North, it was once a similar story. It has been Labour since 1937, with a couple of turbulent SDP years in the 80s; their canvassers have...