Inside Politics:The impact of Wednesday's Budget will be a real test of Brian Cowen's leadership ability.
It will have a decisive bearing on whether Bertie Ahern's heir apparent succeeds to the Taoiseach's office, as most people in Fianna Fáil expect, or whether the ultimate political prize slips from his grasp.
It will be well into next year before it becomes clear whether Cowen's fourth budget will work as he intended. Only then will people know whether it was a finely-balanced, cautiously-optimistic measure that stabilised an economy coming under stress or whether it marked a step back down the slippery slope of borrowing for current spending.
If Cowen's management of the public finances is as shrewd as his management of public expectations in the run-up to the Budget, then everything will turn out well. The voters were conditioned to expect the first tough budget in nearly two decades, so what they actually got came as a pleasant surprise.
The Fine Gael finance spokesman, Richard Bruton, accused Cowen of "bottling it" by failing to take hard decisions about public spending and radical reform in the public service.
While the Minister will benefit in the short term from avoiding unpopular spending cuts and steering away from the hornets' nest of public service reform, he will suffer in the long term if his calculations are wrong.
The return to borrowing for current spending is certainly affordable. As Cowen emphasised in his Budget speech, Ireland has one of the healthiest set of public finances in the EU.
However, there are two potential problems about his return to borrowing.
The first is that if the Department of Finance's projections for tax revenue turn out to be as inaccurate about the impact of the slowdown as they were about the impact of the boom, then borrowing will be much higher than Cowen planned.
The second problem is that Ireland, as an economy heavily dependant on world trade, is at the mercy of international trends. A serious recession in the US could create havoc across the globe, and the impact on the Irish economy would be serious.
These factors could blow Cowen's Budget badly off course but, if his assessment is correct, then everything will turn out all right.
Given his relatively benign assumptions, it was no surprise that the Minister focused his available resources on social welfare recipients, particularly pensioners, as the top priority rather than attempting to give any more concessions to income tax payers.
In line with his previous budgets he adopted a traditional Fianna Fáil approach to managing the State's finances in contrast to his predecessor, Charlie McCreevy, who followed a more economically-liberal path, favouring those in paid employment.
The surprise element of the Budget was the reform of stamp duty. Cowen had publicly set his face against doing anything more than the abolition of the duty for first-time buyers, which he rushed through the Dáil immediately after the election.
There was no hint until a day or two before the Budget that he had changed his mind.
The Minister rejected suggestions that he had caved in to intense lobbying from the construction industry, and insisted that he had made the move on stamp duty to stabilise the housing market.
He defended the timing of the decision on the basis that it was required at this stage, and not six months ago when he made his first move on the issue.
While Cowen deserves plaudits for looking after one of Fianna Fáil's core constituencies, the social welfare recipients, his attempt to cater for that other core constituency of the party, the builders' lobby, is a more dubious exercise.
The Minister went with the argument that the construction industry is so crucial to the economy that it needed a shot in the arm to counter the slump in house prices.
However, there is an even stronger argument that it is time the country weaned itself off dependence on construction as the engine of economic growth. The level of house building in recent years is simply unsustainable, and exorbitant house prices have had a range of hugely negative social consequences. It is about time that house prices started to fall, and in the longer term that will be good for society.
In any case, it is doubtful if the stamp duty changes will do much to arrest the housing slump. Once it has started it may be impossible to reverse the decline until prices drop to affordable levels.
There is such a range of imponderables out there that we probably won't know for the best part of a year whether Cowen has proved to be a calm hand at the tiller at a difficult time or a Minister who refused to face up to the reality that the boom was well and truly over, and failed to see it was time to cut rather than control the rise in public spending.