At a time when people have little confidence in assurances about what is in their food, what their politicians are up to and in much of what the establishment tells them, they were presented with a complex legalistic document with assurances that it was fine. Almost 40 per cent rejected the assurances.
The result is worrying for pro-Europeans, despite their professed satisfaction over the weekend. This was a minor EU treaty by recent standards, backed by the entire political establishment. Yet 40 per cent said No. The next EU treaty will be presented to the people as structural funds and agricultural supports dwindle, and Ireland faces the prospect of becoming a net contributor to the Union.
There is a downward trend in support for EU referendums: in 1972, 83 per cent voted to join the EEC; 70 per cent supported the Single European Act in 1987; 69 per cent supported the Maastricht Treaty in 1992. Now just 62 per cent has supported Amsterdam.
The Lansdowne exit poll conducted for RTE's Prime Time programme showed the most common reason given by No voters for rejecting Amsterdam was lack of information. This bears out the finding of the Irish Times/MRBI poll taken 10 days before polling which showed that 51 per cent of those questioned felt they had not enough information to make up their minds.
However it is difficult to see how anyone who has been living in the State for the past few weeks could believe there was too little information on the issue. The Referendum Commission spent £2 million on an information campaign, and groups and parties on either side of the debate campaigned enthusiastically. Broadcast and print media carried reports on the Amsterdam campaign every day.
These poll responses may reflect more on the quality of the information available, rather than on the quantity. Voters may have been confused by the Referendum Commission leaflets which carried contradictory arguments. The claim and counter-claim concerning the meaning of complex sentences and clauses did little to bring clarity to the minds of many voters.
The campaign did not give rise to a broad philosophical debate on Ireland's position in Europe; the advantages and drawbacks of closer integration; the means to address the democratic deficit in Europe; the details of the future security architecture of Europe and the level of involvement Ireland should have in it.
It concentrated instead on technical disputes over the meaning of sentences in the treaty. On many days the campaign itself was the issue. The row over whether EU Commissioner Mr Padraig Flynn was allowed express a view on the treaty was typical.
The Lansdowne exit poll shows the repeated warnings from the No side that Ireland was being moved by stealth into a military alliance had an effect. While the EU states most keen on developing a common European defence regard Amsterdam as a major setback, many Irish people were worried. Unscientific surveys of No voters over the weekend showed that a number feared their children would be forced to do military service in the future if they voted for Amsterdam.
This scare story first emerged during the 1992 Maastricht debate, when No campaigners suggested conscription into a European army could follow approval of the treaty.
The entire political establishment lined up in favour of Amsterdam has failed to ease the fears of many people on the security/ defence issue. Apart from Fine Gael, most pro-Amsterdam campaigners did not address the changing face of European security and state clearly what they saw as Ireland's postCold War role on new security structures.
Instead, they confined themselves to an "oh yes it does, oh no it doesn't" exchange with Mr Anthony Coughlan, Mr Roger Cole, Ms Patricia McKenna and Mr John Gormley on whether the treaty affects Irish neutrality.
Some Yes campaigners have complained the media gave more coverage to the No side than the Yes side. The truth, however, is that the No side was more active and more diverse. A larger number of groups opposing the treaty held press conferences to launch their campaigns than did treaty supporters. The points they made about the highly complex treaty had more dramatic impact than the generalised assurances from the Yes side.
In the final analysis the complexity of the treaty ensured the high statement of voter opposition to it. The No campaign slogan on posters on the final day - "If you don't know, vote no" - clearly had an impact.
The Irish Times/MRBI opinion poll taken 10 days before polling showed 46 per cent voting yes, 11 per cent voting no, 30 per cent undecided and 13 per cent saying they might not vote. On the day those 43 per cent uncommitted voters went to the No side in a ratio of almost two to one.
Some 33,228 voters spoiled their votes in the Amsterdam referendum - twice as many as did in the Belfast Agreement vote. A further 1,465 who voted in the Belfast Agreement poll did not vote o the Amsterdam Treaty.
Yet it would be wrong for the anti-Europeans to believe this indicated a substantial growth of Euroscepticism in Ireland. The Eurobarometer survey of October/November last year showed Irish public support for EU membership still the highest in Europe. Some 83 per cent believe EU membership is a good thing, with just 3 per cent believing it to be a bad thing. Irish people also expressed the highest satisfaction with democracy in the EU, and had the second-highest level of trust in the EU.
We may trust the EU but a substantial proportion did not trust the assurances from the political establishment that this complex document was unthreatening. This was despite an implicit suggestion that a No vote was a vote against the gravy train. Next time the gravy train may be close to empty.
"Next time we win," said the chairman of the Peace and Neutrality Alliance, Mr Roger Cole, yesterday. The pro-Europeans have some work to do to prove him wrong.