Oliver Letwin is back in the Guardian‘s dock – this time over a few sentences in a 15-year old book which compared drugged adolescents to medieval serfs, and described the former as members of an underclass.  Today’s Observer story is a half-hearted follow-up to last week’s Guardian report of his opposition, while an adviser to Margaret Thatcher in 1986, to proposals by David Young to fund black entrepreneurs.  Letwin co-wrote in a memo that “so long as bad moral attitudes remain, all efforts to improve the inner cities will founder. [Lord] Young’s new entrepreneurs will set up in the disco and drug trade”.

The case for the prosecution is that the third most powerful Minister in the Government is a racist and reactionary.  The case for the defence, put by Letwin himself, is that “one of my greatest concerns ever since entering parliament in 1997 has been to find ways of enabling all our citizens – and in particular the most vulnerable and those caught in cycles of addiction and breakdown – to achieve equality of opportunity and a better life through full participation in the benefits of our society and civilisation.”

A fuller reading of that 1986 memo suggests that his efforts have born fruit.  It proposed to reinforce the family through the law and tax, to set up “old-fashioned independent religious schools” and to change attitudes to personal responsibility, honesty, and the police from an early age including a new moral ‘youth corps’ “.  For tax measures to help families, read David Cameron’s marriage tax allowance.  For independent schools, read Michael Gove’s free schools, faith-based and non-faith based.  For a youth corps, read National Citizen Service – another initiative with the Prime Minister’s own stamp on it.  These are Thatcher-era proposals dressed in modern Cameroon garb.

To say so is not to portray this Government, as some on the Left try to so, as so simply furthering Thatcherism by other means.  There are differences as well as similarities between the Conservative politics of the late part of the twentieth century and the early part of the twenty-first: consider, for example, Theresa May’s curbs on stop and search, or her measures to reduce deaths in police custody, or indeed her claim that Britain’s police forces are “too white”.

These are signs of deeper cultural change.  Letwin’s memo was part of a debate within government about responses to the Broadwater Farm disturbances.  As Trevor Phillips points out in the same paper that carries today’s story, attitudes to black people in 1985 were different on the Left as well as the Right, and some Labour members used language far more biting than Letwin’s in the riots’ aftermath.  The Daily Mirror “put responsibility for the Broadwater Farm disturbances squarely ‘at the door of the black community’ “.  A Labour Councillor in Haringey described Bernie Grant, then his council’s own leader, as being ‘like the leader of a black tribe’ “.

But the Letwin rumpus shows more than how papers hunt for victims, policies change and attitudes develop. What it perhaps highlights most is the capacity of conservatism to reinvent itself as a governing force.  Letwin himself might almost have been produced in laboratory conditions to help prove the point.  The former special adviser to Thatcher is essentially a special adviser to Cameron now – an immensely more glorified one, certainly, but one whose function has scarcely changed in over 30 years: to help develop and implement policy.

At some point post-1997, he clearly concluded that to win and hold office, the Conservative Party would need to present itself anew to a fresh generation of voters.  The young MP who supported John Redwood for leader in 1997 duly became one of David Cameron’s earliest backers in 2005 – having previously immersed himself in Iain Duncan Smith’s Renewing One Nation project.  Some of the policies he oversees today are new and so is much of the language, including his own.  But he is less a symbol of reinvention than evidence of continuity – of the deep instinct for office that has helped to make the Conservatives the longest-lasting party in the world.