It sounds paradoxical to say so, but Mr Cable is a new type of politician. He has knocked about the world, working as an adviser to the Kenyan government and chief economist of Shell. He has unusual personal accomplishment, as anyone who saw his remarkable appearance on Strictly Come Dancing will know. He is the author of the most gripping memoir by an active politician since that by David Blunkett. He has known personal tragedy through the slow death from cancer of his first wife, Olympia. He has rough edges and has enjoyed a genuine career outside Westminster. Alone among the Liberal Democrat members of the front bench, Mr Cable has managed to stay loyal to the Coalition without surrendering his identity.