Louise Casey has what must be one of the most unenviable jobs in government. She is head of the Troubled Families programme, charged for the last three years with making a tangible ­difference to the lives of the country’s 120,000 most problematic families.Truancy, alcoholism, drug abuse, domestic violence, absentee parents, unemployment, poverty: this is the backdrop to every day of these families’ lives, and so inevitably it is the backdrop to Casey’s life too. And, it has to be said, there are sexier bits of government than trying to fix the lives of people whom some consider to be beyond any kind of help at all.Casey, though, has never flinched from any of it. Now 49, her whole life has been more or less devoted to working around people on the margins of society: