On the evidence of his article in last Thursday's Guardian, when Peter Mandelson calls for New Labour to "renew" itself, he really means that he wants the party within the party to go on behaving as it always did. Not even the cliches have changed and the old vacuities are repeated in their well-worn form. No one can complain about the demand for more "investment in infrastructure". Indeed its shortcoming as a defining policy is its universal popularity. The real problem, which politicians must face, is how to bring that desirable aim about. To write "Who cares whether it is publicly or privately financed as long as it actually happens and is well managed?" is a perfect example of how to ask a question and beg it at the same time.  Mandelson seems unable to realise that those of us who believe that the public services should be publicly financed are not crazy ideologues. We subscribe to RH Tawney's view that questions of nationalisation are best decided after examination of specific industries rather than by ringing declarations of principle. In some areas of the economy, the high levels of investment and good management that Mandelson craves are more likely to be provided by public rather than by private enterprise. Ironically, that view reflects New Labour's pragmatic demand to support "what works". It is the government - with its doctrinal faith in the market and free enterprise - that has elevated prejudice above experience.    As I began to read Mandelson's article I hoped that he had at last recognised that simple truth. Transport was omitted from the list of government triumphs. That omission illustrated, at least by implication, an increasingly obvious fact. Most of the government's successes - redistribution in favour of the working poor - have been Old Labour successes. Almost all the failures (the railways being a perfect example) have been New Labour failures. Although his silence on the subject of transport suggests that Mandelson realises what went wrong, most of his article reflects a depressing willingness to make the same mistakes again.   Of course, the railway system suffered from 18 years of Tory neglect. But New Labour has four years of complacent inactivity to live down. The mistakes began in an area of politics in which Mandelson used to specialise - public perception. Back in 1995, it was assumed that the key middle-class voters in marginal constituencies were against nationalisation in any form. The promise to bring Railtrack back into public ownership had to be broken in order to demonstrate a clean break with Old Labour. Incredibly, the prime   minister actually said so on the Frost programme yesterday. Never mind the evidence, read the opinion polls.   Unfortunately the opinion polls got it wrong. So did the focus groups. New Labour was (and for all I know may still be) committed to "continuous democracy" - an election-winning technique invented by Dick Morris, one of President Clinton's confidants. According to his theory, a government that wants a second term must make a new announcement every day and the announcement must always coincide with the majority view of the voting public. Leadership thus becomes a dangerous extravagance.   Philip Gould imported the "rule of 50%" from America and advised the PM about which policies he should adopt in order to keep a majority of the volatile voters on his side. At the time when the government should have been pouring money into the railways, Gould concluded that the general public were not very worried about transport. I expect that he said the subject had a "low salience".   Perhaps he was right at the time. It has a high salience now.   Ministers have taken to whispering that the Railtrack catastrophe is all John Prescott's fault. He is an ideal scapegoat - Old Labour in attitude and appearance if not in philosophy, on the wrong side of 60 and destined for oblivion. He was certainly in charge during the years of complacent neglect, but nobody who has ever talked to him for more than five minutes could possibly doubt his enthusiasm for more investment in transport. Perhaps he was overruled.   And still the platitudes are trotted out as an alternative to thought. "We should adopt the fiscal and exchange rate policies that puts the needs of investment before a consumer boom." I doubt if even Nigel Lawson, who chose the opposite in 1987, now disagrees. But how do we achieve the desired objective in those public services where returns on capital are low and shareholders demand - as the Company Act allows - that their interests are put first? Perhaps the strategic plan for railways, due to be published today, will answer that question convincingly. If it does, it will either break new economic ground or repudiate New Labour thinking.