I have been up in Scotland to see my Mum and speak at the Lennoxlove book festival. Scottish politics is interesting at the moment. Scotland on Sunday asked me for my take and the article they run today is printed here.

The success of political leadership lies on being able to capture the mood of your country, and persuade people that the values and vision you hold – and the policies you put forward – match both mood and people’s expectations.

By that yardstick, Alex Salmond’s campaign of four years ago, though it pains me to say it, has to be judged a success. It was a slick campaign helped by a war chest three times the size of Labour’s, and Salmond proved himself a slick communicator, always on message, always positioning himself on the populist side of as many causes as he could back.

As so many leaders do, however, he has found government harder than opposition. He can still do soundbite politics and, like David Cameron in Westminster, does not lack front or self-confidence.

But both, in different ways and on different timescales, are finding that the spin and the soundbites only take you so far. For enduring political success, such as the three general elections won by Labour, you need substance, a real understanding of people and the times we live in, and, above all, you need the detailed, thought-through policies that deliver change.

Like Tony Blair, Salmond had a long honeymoon. The media lapped up clarity of message, which he delivered well and which acted as a clever soundtrack to the music of an upbeat, devolved Scotland. But his big mistake was thinking he could get by being a good communicator with a man-of-the-people touch. Politicians who don’t have the policies and are unable to improve people’s lives get found out. Governments are judged on what they do. Words, however well polished, are never a substitute for real change.

Even as I write those words, I can see the Salmond guffaw – the one he deployed for Iain Gray’s attack last week that his limited and confused Budget put party before country – at the idea that I of all people should be talking about actions speaking louder than words.

I have just finished editing my next volume of diaries (out in January, now you ask), which cover the first two years of the Blair government. The five pledges that we made the centrepiece of our campaign – all met. Then Bank of England independence, a minimum wage, the New Deal, a Scottish Parliament, the beginnings of the biggest investment in schools and hospitals since the creation of the NHS, peace in Northern Ireland, welfare reform, gay rights, Kosovo, Sierra Leone… I could fill the whole of this page with a list of major changes made in a short period.

What can Salmond and the SNP say by way of comparison on record over the years they’ve had? They certainly raised expectations in 2007, but unlike New Labour a decade before, have not fulfilled them. The litany of broken SNP promises, born out of a manifesto that over-pledged, grows weekly.