Just 12 months into the job, he is already credited with being the intellectual force behind the Conservatives' decision to admit publicly that Labour has changed, while insisting it is still unfit to govern. Less to his credit is his part in writing the 24,000-word spoof of Labour's draft manifesto, Road to Ruin, widely acknowledged to have been in poor taste.
As befits a former co-director of the Social Market Foundation, his vision of education is one in which an internal market rules. In an ideal world, Mr Finkelstein would probably like to see a system that allows private promoters to set up schools, thereby creating greater choice on what market analysts like to call the supply side.
Such promoters, the thinking goes, would be sensitive to parental wishes and that could mean the restoration of grammar schools. Thus, it might be possible to achieve selection and the paperless voucher in one fell swoop.
The scale of Mr Finkelstein's conversion from youthful member of the Labour party to the right wing of the Conservative party is dramatic, but not unprecedented.
He joined the Labour party at 16, defected to the Social Democratic Party two years later and then, just before the 1992 election, he led a group of former SDP activists into the Conservatives under the banner "Social Democrats for Major".
During his period in the SDP he became political adviser to David Owen and stood for Parliament in Brent East against Ken Livingstone in 1987. Afterwards, the SDP merged with the Liberals to form the Liberal Democrats, but Dr Owen and his supporters broke away.
The Social Market Foundation, of which Daniel Finkelstein was a co-founder, has established itself as the most influential of the independent think-tanks on the centre Right, making the case for internal markets in health, education and other public services. He was replaced at the SMF by Stephen Pollard, who departed from the Fabian Society in the wake of a panegyric he wrote in favour of grammar schools.
In articles he has contributed to the The Times, Mr Finkelstein has displayed a particular interest in the revival of the American Right and the lessons that can be learned from their experience.
Mr Finkelstein's period at Central Office has coincided with a worsening of relations between Gillian Shephard at the Department for Education and Employment and party headquarters. Brian Mawhinney, the party's chairman, has denied reports earlier in the summer that he had been pressing for more effective attacks on the Labour opposition from Mrs Shephard.
In the struggle being waged over the content of the manifesto, Mr Finkelstein is likely to be the advocate of radical right-wing policies.