Mitt Romney teaches the Tories a lesson in conviction So startling, in fact, that the Left-liberal legions in America were staggering around for 48 hours mumbling, "What just happened?" Al Gore actually suggested that Obama's astoundingly poor showing could be blamed on the altitude in Denver, Colorado. I did not make that up. In fact, both the Romney and Miliband performances benefited greatly from the element of surprise: they were both so breathtakingly unexpected. Added to the genuine impressiveness of the occasions themselves, there will have been an electorally advantageous element of self-reproach on the part of the audience. ("I have been unfair to this man. He is more worthy than I had assumed.") Not only will voters have been affected by the specific event but, in their desire to make amends for their earlier misjudgment, they will now be more likely, at least for a while, to give Romney/Miliband the benefit of the doubt. In truth, the very different political orientations of Mr Miliband and Mr Romney make what their rehabilitations do have in common all the more interesting. They both, from their opposing directions, spoke of politics as a moral mission, and they described their personal belief in the values that drove them into public life with a fervour that rang true. In the end, whether you agreed with them or not, you really did believe that both men were running for office because they were dedicated to an idea of the greater good. There was not only passionate conviction, which many of us have tried to promote, without success, to those smug packaging experts who dominate the Cameron project. But there was also intellectual energy - what you might describe as an enthusiasm for argument itself. This was what was especially surprising about the Romney/Obama clash: Romney, the supposedly dull businessman, seemed more eager to engage in actual debate than Obama, the idealistic academic, who looked languidly bored with the whole endeavour. I don't think it's possible to state this too strongly: to imply that argument is beneath you or that you find it a waste of time is tantamount to treating the electorate with contempt. Argument is what democratic politics is about. It does not always have to be abstract or theoretical - although basic principles must underpin it. But even quite unsophisticated voters now feel, however vaguely, that politics must be about something: that a politician's ambition should be in the service of an idea. Otherwise, the desire for office is nothing more than self-aggrandisement. It is not for me (God knows) to declaim on what Mr Cameron truly believes or wishes to stand for. But I do know that whatever it is must be so patently authentic and consistent with his personality that it resonates effortlessly in every speech and statement that he makes. At the heart of both the successful Romney and Miliband appearances was a persistent thread: this is what makes me what I am. Mr Miliband made the "one nation" theme sound convincingly as if it had sprung from his refugee roots. For Mr Cameron to try to reclaim it for his party now (however tempting that might be) would look pathetically imitative: Mr Miliband has made it part of his moving autobiography and there, for the moment, it must be left. Mr Romney drew his commitment to individual freedom and the liberating power of personal prosperity from his experience of wealth creation. This is rather more plausible ground for Mr Cameron - as is the unashamed Romney rejection of overweening ("trickle-down") government, and his fearless embrace of tax cuts for middle-income earners as a way of stimulating growth. Which brings us to the question of practical policy. The Tories - and more especially, George Osborne - are going to need some good headlines this week. That means nice surprises. And that means tax cuts for middle-income people. Suppose that the Chancellor were to announce that in exchange for the Liberal Democrats" mansion tax on properties worth over one (or two) million pounds, he was going to abolish inheritance tax on all estates worth less than that amount? That might go some way to placate Mr Miliband's "squeezed middle." The Tories need to make a start at re-invention of a very different kind from the vanity project of the past five years: it is not about being "modern" (whatever that means) any more. It is about competence and coherence - about having something substantial to say to real people, and looking as if you mean it.