The warning signs have been there for some time. First, there was the 51 per cent who, in the second Irish Times/MRBI poll, felt at best that they were only vaguely aware of the issues. Second, and more ominously, that same poll tracked a remarkable alteration in opinion on what Ireland's stance vis-a-vis European integration should be.
In 1996, when this was first measured, 55 per cent felt the statement "Ireland should do all it can to unite fully with the European Union" was closest to their own view, as compared with 32 per cent who preferred the statement "Ireland should do all it can to protect its independence from the European Union" (the residual percentage had no opinion). Support for further integration slipped to 46 per cent in 1998 at the time of the Amsterdam referendum (see accompanying chart), though without, at that stage, any increase in the pro-independence option.
However, by the beginning of the Nice campaign, pro-independence sentiment had grown by 15 percentage points from its 1998 level. And, with a week to go, this trend was still observable and the independence option had edged a fraction ahead.
On the turnout and the No vote the questions are: why and what are the implications?
It must be emphasised that those who stayed at home were a mixed bunch. A substantial proportion would be persistent abstainers, who, from the point of view of a European contest, are a different challenge. Another substantial proportion of last Thursday's abstainers were "circumstantial abstainers", that is electors who would have voted but were prevented from doing so by circumstances.
The remaining abstainers were what might be described as "Nice-specific voluntary abstainers", that is electors who did not vote because of something in their attitude to the referendum and/or the treaty. These were the ones who really mattered. Who were they and why did they not vote?
Precise answers will require further research (which, in the light of the rate of abstention and the need to know what it is that voters took exception to, would seem to be essential). In the meantime, however, we can get a tentative handle on the sources of abstention by analysing the causes of variation in intention to vote as revealed in the second Irish Times/MRBI poll. If this analysis is done using multivariate statistics, we can begin to assess particular effects while holding other factors constant. The results suggest that, as usual, young people, especially those under 25, were less likely to vote. People living in rural areas, other than farmers, were also less likely to vote. Being middle class (ABC1) increased the probability of voting, as did being a farmer. And being a supporter of any of the political parties, except, for some reason, the Labour Party, also helped. But the crucial factor leading to abstention was the feeling of not understanding the issues.
We can apply the same technique to the question "what led people to vote No". Was it the Rapid Reaction Force and neutrality? Was it the commissionership or the changes to Ireland's voting strength? Was it a more general reservation about an intensifying European integration? Or, as in the Amsterdam referendum, did those who "did not know, vote No"?
The biggest factor leading to a No vote was the growing pro-independence sentiment doc ument ed at the outset of this article. This outweighed the influence of any of the specific aspects of the Nice Treaty measured in the poll. However, several of these also had an effect.
In order of magnitude and coming some way behind the pro-independence sentiment, these influences were opposition to participation in the Rapid Reaction Force and the unacceptability of the provisions on the commissionership and the reweighting of votes. Surprisingly, and in contrast to Amsterdam, those who went to the polls feeling they did not fully understand the issues tended to vote Yes.
The analysis also shows that expected major boosts to the Yes vote from the middle class and from farmers that might have been expected failed to materialise. As we have seen, both these groups were more likely to have turned out to vote but, if they did so, it was not because of any substantial benefit to the cause of ratification (this is quite compatible with some indications from the results and the tallies that there was some more support for ratification in middle-class areas).
Finally, the evidence suggests that the Yes vote did get a bit of a boost from two unexpected quarters, namely women and people aged 25-34.
And the implications? First, the fact that lack of understanding appears to have been the main cause of extraordinary abstention means that we must examine how we conduct all aspects of referendums. And "all aspects" include the role of the Referendum Commission and the constitutional constraints on the conduct of referendums as interpreted in the McKenna and other Supreme Court judgments.
The second implication arises from the indications that a general sense of reservation about further integration was the main factor driving the No vote. This reservation has complex roots and there is some evidence it is more prevalent among older people and among those with skilled-manual and unskilled-manual occupations.
It may reflect concerns ranging from traditional Catholic morality to Irish neutrality and Ireland's international role in an era of globalisation. Its overriding influence certainly makes the Government's job of responding to the result more difficult and may mean it will have to concentrate as much on persuading the Irish people as on negotiating a new deal with its European partners.
Prof Richard Sinnott is Director of the Public Opinion and Political Behaviour Research Programme at the Institute for the Study of Social Change at University College Dublin.