Steve Richards: David Cameron is just after a quick hit in the polls

He gives a clue that he is seeking to trap Labour into being the party that stands up for benefit cheats

David Cameron is starting to sound as reactionary as his policies. His policies are rooted firmly on the right but until recently, his tone was compassionate and progressive. The Prime Minister's speech yesterday on welfare reform marked a new realignment between tone and substance. As he listed a series of proposals to cut benefits from the young and some families, the Prime Minister did not even affect a reverence for Harold Macmillan or Disraeli, genuine one-nation Tories who, unlike Cameron, also sought to follow one-nation policies. Instead, the headline-grabbing initiatives poured out, the flow undisturbed by too many forensic facts and figures.

Cameron claims, and probably genuinely believes, that he is following Tony Blair's example by moving his party to the centre ground. In fact his early strategic contortions were subtler. To take one emblematic example, Cameron used to say famously that there was such a thing as society but that this was not the same as the state. The declaration generated a thousand headlines about a new moderniser moving away from harsh Thatcherism. In reality Cameron's argument about the virtues of a smaller state was precisely the one that had been advanced by Margaret Thatcher.

Behind Cameron's reassuring façade his advisers Steve Hilton and Oliver Letwin planned a small state revolution, George Osborne announced unprecedented spending cuts, Andrew Lansley wrote a White Paper aimed at breaking up the NHS, Michael Gove created the space for a schools' revolution including a degree of stealthy selection at secondary school level, Iain Duncan Smith unveiled the most wide-ranging shake up in welfare since the post 1945 Beveridge settlement, an astonishingly radical agenda for a party that did not win an overall majority. But Cameron's early genius was to continue to project a modern, centrist leadership. Hoodies wanted love. He was pro-welfare because he was pro-families. He addressed the TUC but not the CBI. He wanted a windmill on his house because he was a passionate green. The three letters he cared about were NHS. It was an almost mesmerising re-heating of Thatcherism in a modern context.

Yesterday's speech on welfare reform was different. There was not a hug or a windmill in sight. Worried by opinion polls and attacks in still-powerful right wing newspapers Cameron has seized on a policy that was popular a few months ago, the cuts in housing benefit, and turned it into an argument for a wider onslaught.

The questions he raised in the speech are valid, but Cameron took them out of any context. Should young people qualify for housing benefit when low earners live at home? Should families with large numbers of children get child benefit when the parents do not work? Why is there such a damaging gap between those who struggle on poor pay and those on benefit? They become provocatively superficial questions unless accompanied by at least some recognition of reality and a hint of practical policy implementation. Even graduates from top universities struggle to find work in current economic circumstances.

While they are looking they need somewhere to live and not all of them have parents in areas where there are vacancies. No doubt there are some who do not seek work. How does he envisage making an informed distinction? No wonder he dropped from the final speech a proposal for regional unemployment benefit levels. The Coalition struggles to implement its current plans for regional pay in the public sector without having to decide how much an unemployed claimant is worth in Cumbria compared with Kent.

Yet this is to treat the speech as if it was the product of a thought-through policy agenda instead of one in which Cameron seeks a quick hit in the polls and within his restive party. Iain Duncan Smith sounded uneasy in interviews yesterday. The actual detailed policies from Cameron's speech must wait another day and more likely another few years.

When Cameron and George Osborne proclaimed cuts in child benefit for high earners they had a policy without an argument. Now Cameron has an argument without precise policies. Thus Cameron gives a further clue that he plans to fight the next election on a more tonally populist platform, seeking to trap Labour into being the party that stands up for benefit cheats.

The move will not succeed partly because of Cameron's earlier pitch. Successful political leadership is the equivalent of writing music in which all parts cohere. In the case of politics, policy, principle and projection must work in harmony. Cameron moves from "Yesterday" to Yoko Ono's primal screams from the late 1960s. At the very least such atonal leaps raise questions about a leader's authentic voice.