Labour hoped devolution would persuade voters that Scotland did not need independence and that, consequently, nationalism would be killed “stone dead”.

That, in turn, would help ensure the party at Westminster could continue to rely on a substantial body of Labour MPs being elected from north of the Border.

True, in agreeing that the new Parliament should be elected by proportional representation, Labour had accepted it might not be able to win an overall majority and might need to share power with the Liberal Democrats.

However, that decision had the virtue that it would be virtually impossible for the SNP to win an overall majority too.

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Meanwhile, many advocates of devolution – from all parties and from none – hoped the new institution would become the fulcrum of the nation’s political life and bring voters to the polls.

However, the result of the first election contained plenty of warning signs that these hopes and aspirations would not necessarily be fulfilled. At 58 per cent the turnout was well down on the 1997 UK General Election – and indeed every other post-war election before that.

This cast doubt on the idea that the new institution would strengthen the connection between politics and the citizen.

Meanwhile, the SNP won 29% on the constituency ballot and 27% on the crucial regional list vote – more than the party had ever achieved at a Westminster election apart from October 1974.

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The 35 seats it was allocated by the new electoral system meant the SNP became a significant full-time parliamentary force for the first time.

This did not look like a one-off performance. Polls revealed that people were more willing to vote for the SNP – and less likely to back Labour – in a Holyrood election than they were in a ballot for Westminster.

Voters were more inclined to decide on the basis of what they thought was best for Scotland rather than for the UK as a whole. That favoured a party that promoted itself as “standing up for Scotland”.

Still, Labour, with 56 seats emerged as by far and away the largest party, albeit nine seats short of an overall majority. It was easily able to form a coalition with the Liberal Democrats who, it seemed, could look forward to many years in office as the party without whose support it would be impossible to form an administration.

Meanwhile, in 2003, the second election saw the Labour/Liberal Democrat coalition returned to office, albeit with diminished Labour representation.

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However, the level of turnout remained relatively low. In the four elections held between 2003 and 2016 it did little more than hover around the 50% mark, averaging just 52%, well below the equivalent figure (64%) for Westminster elections in Scotland – even though there has been a gradual increase in the proportion of voters who think the devolved institutions rather than Westminster have most influence over the way Scotland is run.

Meanwhile in the third election in 2007, the devolution story took a dramatic new turn. The SNP managed to win one more seat than Labour. The Liberal Democrats decided they did not want to be part of a government that wished to hold an independence referendum.

However, they and everyone else agreed that the SNP should be allowed to form a minority administration. Labour suddenly found itself out of power, while the Liberal Democrats no longer had much influence.

The rest of the story is, of course, well known. The new electoral system failed to deny the SNP an overall majority in 2011. That paved the way for an independence referendum in 2014 which, although it produced a majority in favour of staying in the UK, registered a much higher level of support for independence than had seemed likely when the campaign began.

That in turn was followed by a remarkable swing to the SNP in the 2015 General Election, with the party winning 50% of the vote thanks to an apparent determination by those who had voted Yes to independence to affirm the choice they had made.

Not only did Scotland’s position in the Union now seem less secure than ever before, but Labour’s domination of Scotland’s representation at Westminster had been reduced to rubble as voters lost their relative reluctance to vote SNP in a Westminster ballot.

That, of course, does not mean that everything has since been plain sailing for the party. In 2016, it was unable to secure a second overall majority at Holyrood, while in the 2017 UK election, the party’s 50% vote fell back to 37%.

Even so, the party that was meant to be killed “stone dead” is more than very much alive, while Labour now finds itself Scotland’s third party at both Westminster and Holyrood.

Scotland’s devolution story has underlined how constitutional change can have unintended consequences.

Sir John Curtice is Professor of Politics, Strathclyde University.