Looking back on 2007, it seems amazing that no-one seriously expected the SNP to win the May Scottish elections." Or so I wrote in this column 12 months ago in a piece imagining how Scotland would look in a year's time. Truth is, I genuinely didn't believe that the SNP would win Holyrood, even as I was forecasting it. The thinking among the Scottish political classes was that, whatever the polls said, the voters would turn back to Labour on the election eve. Many did, of course, but not enough. And the history of Scotland, and the UK, has been rewritten as a result.

May 3, 2007, was an extraordinary night, and no-one who cares about Scottish politics will ever forget it. As Labour and the Nationalists fought it out, hour by hour, seat by seat, the election nearly descended into chaos. Ballot boxes got washed away in the isles, computers went awry and in Edinburgh a man with a golf club attacked a number of ballot boxes. Then there was the "re-engineered" ballot paper, which bamboozled more than 140,000 voters.

It wasn't until 5.32pm the next day that Scotland's new political landscape finally emerged. For the first time in 80 years the SNP had actually won an election - at least, that was what most of us thought. But within the hour, the Labour first minister, Jack McConnell, announced that, no, this was a "magnificent result for Labour", and that it was going to be business as usual.

With hindsight, this looks like the most monumental arrogance, and Labour have been punished for it, but at the time it didn't seem so daft. After all, the SNP had only returned 47 seats out of 129. Labour had 46, the Tories 17, Liberal Democrats 16, the Greens 2 and Independent 1. If the Tories had abstained, Labour and the LibDems could have formed another government. In fact, looking back on the past nine months, the remarkable thing is that the SNP are in government at all, let alone driving events so confidently.

When the LibDems rejected coalition talks, most of us thought that the SNP would be blown away by what Labour MSPs were calling a "pan-unionist grand coalition". The numbers just didn't add up. How would the SNP get any legislation with only a third of the MSPs and no partnership agreement? But, paradoxically, it was rejection by the Liberal Democrats that made the success of this first nationalist administration possible.

It was Alex Salmond's political genius to recognise the opportunity presented by minority government and to build a moral case for it in a series of speeches that will go down in history as definitive statements of the new politics of devolutionary consensus. The first minister-elect insisted that the "founding fathers" of Scottish devolution, the Scottish Constitutional Convention, had argued for minority government in the Scottish Parliament as a matter of choice. He would oblige. Salmond promised to govern, not in party interest, but "wholly and exclusively in the national interest" and to "appeal for support policy by policy in the parliament".

In the end, for all the talk of appealing, Alex did pretty much as he pleased in the next 100 days, using his executive powers to drive through an astonishing range of initiatives and reforms with no particular consensus sought. Saving hospital A&E departments, abolishing prescription charges, bridge tolls and student fees, freezing council tax, cutting business rates, axing government departments and quangos such as Scottish Enterprise, rejecting nuclear power, opposing Trident, replacing PFI and ending private involvement in the NHS. It was impossible to keep up.

In the process, Salmond has created a new form of progressive nationalism, unlike anything seen in Europe in the past three decades. The image of nationalism as a backward and narrow-minded political force, preoccupied with ethnicity and hostile to foreigners, has finally been dispelled. The SNP has made a reverse takeover of the Scottish social democratic consensus that Labour has presided over for the past half-century.

Instead of the SNP being blown away by the unionist majority, Labour were almost blown away by the sheer verve of Salmond's hyperactive administration. Labour end this annus horribilis in a terrible state, with a leadership crisis and a donations scandal. The new Labour leader, Wendy Alexander, has failed to offer any intellectual challenge to Alex Salmond's populist nationalism, and the party organisation is disintegrating.

Labour have feigned opposition to SNP initiatives on issues such as bridge tolls, prescription charges, graduate endowment, and then ended up supporting them. In fact, it is hard to find much that the nationalists have done in the past nine months that Labour really oppose as a matter of principle. They even support Donald Trump's blessed golf course. The truth is that the SNP were doing a lot of things that Labour MSPs would have liked to do, but couldn't because of the London connection.

Despite being only one seat behind the SNP, Labour have yet to mount any coherent opposition in Holyrood, and have ceded the initiative on many key issues - such as police numbers, trams, class sizes - to the Tories and the Liberal Democrats. Even on the constitution, the Labour Party has now joined with the SNP and the Liberal Democrats and - incredibly - the Tories to campaign via a constitutional convention for more powers for Holyrood.

For the first time, all the parties in the Scottish parliament are committed to further constitutional change, including taxation. Nothing could better demonstrate just how much things have changed in Scotland in the past year than the fact that there is now no-one arguing for the constitutional status quo.

And who could possibly have forecast, 12 months ago, that nationalists would not only be in power in Scotland, but also in Northern Ireland and in Wales. Progressive nationalism is now the most potent political force in Britain.

Alex Salmond may have been radical in office, but in one sense he has been profoundly conservative. He has become a Privy Councillor and insisted that Queen Elizabeth II will remain head of state of an independent Scotland. The SNP are now talking about the "social union" with England remaining, even when Scotland wins political independence. This is a recognition, I believe, that the UK still has a future, and that the SNP has come to terms with the modern world. Whether the modern world has come to terms with Alex Salmond remains to be seen.