When British politics reaches a low ebb, I find myself turning to YouTube. Not just for videos of skateboarding cats or dogs that don't want to have baths: sometimes, I'll cheer myself up with a speech made by the 1970s US civil rights icon Harvey Milk. "There's hope for a better world, hope for a better tomorrow," he tells a cheering audience. "I know you cannot live on hope alone, but without it life is not worth living." Ah, what a line.