David Davis's warning to his party to show discipline and stick to the centre ground in today's Sunday Telegraph is the best news for the other David in a while. Davis is scarcely a woolly liberal, a Soho brand manager or a tree hugger. His voice reaches parts of the party Cameron cannot reach. Well-read and supremely intelligent, Davis is in a different league to John Prescott: Davis would make a fine party leader, which is something that could never have been said of Prescott. But Cameron should be using Davis much, much more as a public guarantor of his party reforms, just as John Smith and Tony Blair used Prescott. It is often said that the Cameroons are obsessed with aping New Labour. It is just as arguable that they are not obsessed enough. Blair understood that assembling a tiny clique to drive through his Project was not enough. He needed to build a coalition inside the party to ensure majority tolerance of changes that many Labour members, by definition, would find objectionable. Dave needs a similar range of allies. In this respect at least he needs to be more like Blair rather than less so.