Chancellor's successful argument for fixed-term parliament means he can stick to his course even as public spending is cut
The budget would not have been possible but for a piece of legislation being hotly contested in the Lords only 48 hours earlier: a fixed-term parliament.
George Osborne, the Conservative's supreme strategist, has always argued he could not undertake such major and, in the short term, unpopular structural economic reforms – the bulk of them announced in last year's spending review – unless he was confident the next general election would be held in May 2015.
Osborne personally negotiated hard for a five-year term in his talks with the Liberal Democrats at the time of the coalition's formation. The central deficit reduction programme is dependent on the five-year timetable. This timetable, in turn, gives the chancellor the belief that he can stick to his course, even as incomes are squeezed and public spending is cut over the next three years. He is immune to the revenge of voters.
Labour knows this as well – which is why its peers are working hard to shorten the fixed term to four years, a reduction that would disrupt Osborne's carefully laid path to the next election. But the Conservatives are confident they will defeat Labour peers, and are equally certain that their battered Liberal Democrat colleagues will remain in the coalition until 2015.
Nick Clegg had some tax cutting wins in the budget, notably on personal allowances and green infrastructure.
Clegg has nowhere else to go, and like Osborne he must wait to see if the dice rolls his way on the deficit. Osborne can revel in such security, look at the tottering European governments such as the Portuguese, and breathe a sigh of relief.
Faced by forecasts of rising unemployment up to 2015, a growth slump in 2011, low bank lending, rising inflation and low house prices, Osborne could still reject plan B. Moreover, the latest Office for Budget Responsibility forecasts published on Wednesday show that despite the lower-than-expected growth in 2011 the trend growth rate will be a respectable 2.9% a year in 2014. This growth bounce-back is built into the OBR model. Even though higher-than-expected inflation means £12.6bn higher social security payments and £17.6bn higher debt interest payments, these do not make it more difficult to meet Osborne's chosen target: eliminating the structural deficit by 2015.
The OBR still says the government will meet its fiscal target – putting the cyclically adjusted current balance in surplus – in 2014-15, a year earlier than Osborne had committed himself.
That would leave Osborne free to make election-winning tax cuts as early as the final two years of the parliament. He gave a strong signal in the budget that the 50p upper rate of income tax would go shortly.
The cushion of the five-year term also allowed Osborne to credibly set out some slow-burn reforms such as a single flat-rate pension for future pensioners, the long-term merger of tax and national insurance contributions, linking pension age to longevity, planning reform, a carbon price and a public-sector pension reform built on the proposals of Lord Hutton, the former Labour cabinet minister.
These are long-term plans; some are reminiscent of Nigel Lawson, Thatcher's chancellor, but others can be pursued on an all-party basis. Either way, Osborne can reasonably cast himself as a politician with a wider agenda than shrinking the welfare state.
But all this long-termism does not mean Osborne is insensitive to the public mood and the need to help where the pressure is strongest. He is too political for that.
His public manner can be one of arrogant disdain. On Tuesday he told chortling Tory MPs the only organisation making representations to him to slow the pace of deficit reduction was the Guardian. But in private he runs a heterodox salon at No 11, listens to argument and admits to error. He is frank enough to admit critical mistakes in the election campaign.
He is also enough of a student of American politics to believe in the "permanent campaign", the constant weekly battle to establish a party's ideas and popularity. He was remorseless at the start of his speech, lambasting Labour's failed debt-fuelled model of growth by repeating over and over: "We are paying for the mistakes of the past."
Osborne knows the government cannot afford to be seen as inflexible or unconcerned by social divisions. The demonstration organised by the TUC for Saturday will be the first big test of that cohesion.
Equally, the government does not want its poll unpopularity to become entrenched. With this in mind, the headlines sought in this budget are more about easing the pressure on living standards not the pursuit of growth. Ed Miliband's rhetoric about the squeezed middle has had an impact: hence the slowdown in fuel prices, help for first time buyers and the raising of personal tax allowances.
The chancellor's aides argued: "The losers are oil companies, tax avoiders and carbon intensive energy like oil and coal. The winners are motorists, income tax payers and companies that invest in the UK."
Nick Pearce, a former Gordon Brown aide, admitted the money-raising measures were familiar from the Labour days.
The fiscally neutral budget can hardly be seen in isolation because voters and companies from April onwards will face 82 tax and benefit measures, some of which were brought in by Labour.
Although the Treasury lists the money each of these measures will raise once inflation forecasts are included, it does not tot up the total By one estimate it amounts to an astonishing net extra tax take of £31.9bn in 2015-16.
So while Osborne may be putting fuel in the tank of the British economy, he is at the same time siphoning out so much he has to hope it can get beyond the forecourt.