Gamble's thesis is that the decline of social democracy led by the end of the sixties to the end of the great boom which had lasted since the war. If I have understood him right, this was because of the decline of the dollar which underwrote world currency exchanges and the subsequent quadrupling of oil prices. These things led to free-floating currency exchanges with all national economies constantly reinventing themselves according to a Keynesian template and tripping over each other which in general led to stagflation.
The Keynesian doctrine of government intervention in the economy was past its sell-by date and Thatcher and Keith Joseph in this country and Reagan in the US rewrote the script along with help from Milton Friedman and Hayek which now included items such as the drastic reduction of Union power, a more authoritarian state, the end of the corporate government in which the elected government was in partnership with stakeholders like Unions, and an end to any commitment to equality. Only with a brave and wholehearted commitment to let the market dominate could economic health be restored.
Some years ago I read Thatcher's autobiographies and Gamble's line is consistent with her own. The fundamental driving motive in her government was the economy: the Unions had to be smashed.
What Gamble highlights to me was that Thatcher's courage was extraordinary. She really went for it right from the beginning and in her early years was isolated within her own party; no-one believed she was really going to go through with it. When she was elected we were in a recession, she had mega-low ratings but she didn't give an inch. The Falklands War was a big help and she won a complete victory in the miners strike.
In my opinion it all started to go wrong with the Westland affair. Heseltine wanted to be on board and he was passionately devoted to supporting certain European interests. Thatcher disagreed but man-management was never one of her skills and after she alienated him none of her supporters felt they knew where they stood and they gradually dropped away. Gamble doesn't quite say this, it's just my opinion.
There's a lot of material in here about Thatcher in the context of Conservative party history and whether she was in the tradition of Toryism or not. Also there is some very interesting material drawing on New Left Review opinions dating from the sixties about Gramsci's concept of hegemony which is really looking at British approaches to government going way back.
There's a lot of material for thought about what democratic government should or should not be and an excellent understanding of Thatcher who after all made the market dominated mess we are in now possible. Read and weep.
One caveat. I feel there is some repetition in this book, especially in the long last chapter which basically recycles what has been said earlier in the book. Nevertheless this is cogent, readable, and relevant at all points.