A very good, and revealing depiction of a world that most middle-class people do not see, but that the author has had direct contact with. The huge majority of politicians are lawyers or businessmen, but Dalrymple is a doctor who therefore has much more personal contact with the 'underclass'. The media is full of self-styled intellectuals who have all sorts of theories about poverty and teenage pregnancy, but who don't have any idea what these people are really like.
The writing is very good, but the author does have a slight tendency to express him in too high-falutin' a way (most obvious in his pseudonym -- I mean, Theodore Dalrymple?).
The biggest problem is that Dalrymple thinks that Britain's problems are all caused by liberal and left-wing intellectuals who have brainwashed everyone with theories that criminals are not responsible for their crimes, that children don't have to be taught anything at school, that the police are all brutes, etc. Partly he is right. He is very good at describing the hypocrisy of the chattering classes. Public intellectuals play a role in how the well-meaning middle class are taught to think about social problems. But he is so obsessed by criticizing these 'intellectuals' that he overlooks more convincing possible explanations for the problems he describes. He is a little like Noam Chomsky, who can say insightful things about American foreign policy but constantly gives the impression of thinking that American foreign policy is responsible for all the world's ills.
Many of these social problems, e.g. drug use, high crime rates, child abuse, failing schools, and teenage pregnancy are also prevalent in places like the American South, where 'liberal' is a swearword, where jail sentences for even trivial crimes can be extremely heavy, where a large percentage of the population goes to church and where politicians talk about family values all the time.
The decline of manufacture, globalization, consumerism, the tabloid press, the increasing power of corporations - these are also factors in creating the underclass. It's large entertainment corporations that produce trashy television, the cult of celebrities, etc. -- not la-di-da Marx-reading intellectuals. The fact that many British white working class people can't cook but eat only junk food -- well, I don't know WHY that is, but it's companies like McDonalds and Coca-Cola that encourage it. And this trend is even more obvious in America.