We’re on the train to Ramsgate in Kent and Emily Thornberry is giddy at the prospect of a Saturday morning spent canvassing. “I love it. I know it seems weird, but it’s the bit of the job that I genuinely like the best,” says the MP for Islington South and Finsbury. “I like knocking on the door, not knowing who’s going to answer, what their attitude is going to be, what smells will come out of the door and, in Islington, whether they will be wearing any clothes.” Pardon? “In Islington, people constantly come to the door not wearing any...