WHO would have thought that the SNP would stage the most successful party conference of the season? Labour were at war with themselves, the Liberal Democrats shell-shocked ,and the Tories accident prone. The nationalists, by contrast, seemed united, confident, businesslike, purposeful.

Hasn’t always been so. I have been to too many nationalist conferences which were little more than an intoxicating shambles. The SNP have traditionally attracted a querulous fringe ready to girn and grumble to order. Fundamentalist malcontents who would mutter about betrayal of the faith. Alex Salmond used to be renowned for going over the top followed by swivel-eyed tartan loons.

Not this year. Salmond’s speech wasn’t a masterclass in political oratory, like Tony Blair’s, but it was a first-class leader’s speech delivered with genuine conviction and a minimum of ad hominem abuse. Retread he may be, absentee landlord even, but Salmond saw the occasion and rose to it.

Now, speaking personally, I rather like a bit of political abuse, and Salmond does adversarialism better than anyone in the business. All the more impressive, then, that he held his instincts in check and delivered his pre-election conference address with an air of calm authority, which seemed to come almost as naturally to him as going for the rhetorical knee in the groin. Salmond is a crowdpleaser who has realised that playing to the prejudices of his own party may not be the best way to please the wider electorate.

Even the SNP’s air of hasty improvisation seems to have gone. This conference went like clockwork in the new glass-and-blond-wood Perth conference hall. In fact, SNP staffers seemed to be as organised and on message as New Labour once were. Which is kind of scary, but a refreshing change from the SNP’s enthusiastic amateurism of the past.

The policies on local hospitals, schools, student debt, renewable energy and business taxes were rolled out clearly and efficiently. True, they weren’t properly costed overall (the chancellor will do that for them) and it was a little rich for the SNP to start calling for higher drink prices after decades demanding cuts in whisky duty.

But at least they had some policies, unlike some parties you could mention – led by people called “Dave” – who seem to think that policy is a dirty word. I was reminded of Labour’s election pledges before the 1997 election, which undersold the party prospectus. And at least in Perth prominent nationalists didn’t run around accusing each other of being delusional control freaks or liars. The SNP is the only party with two leaders – Salmond and the Holyrood leader Nicola Sturgeon – who don’t seem to be fighting with each other.

So, what has gone right? Is Sir Tom Farmer’s money already reaching the parts Sean Connery’s could not reach? Well, the SNP have been quietly getting their act together for some time now, and have been trying to formulate a coherent policy agenda instead of a post-independence wish-list.

The experience of the Scottish parliament has been upsetting in many ways for the nationalists. But the discipline of participating in a real legislative forum for seven-and-a-half years has forced the SNP to become more professional and accept the compromises involved in being a party that aspires to government.

It still tries to appeal to anyone and everyone, but it has become better at managing expectations and downsizing its commitments to pressure groups and special interests.

I think the SNP have also come to terms at heart with the fact that independence, as they traditionally conceived it, is an anachronism. Now, of course, no-one says this publicly in the movement, and even privately, they remain nationalists. But there is a much more realistic and incremental approach to national freedom, which is now shared by a wide range of non-SNP opinion in Scotland.

The SNP also have arguably the most effective leadership in Scottish politics. Salmond took a huge risk returning after resigning five years ago to spend more time in Westminster. He could easily have been cast as yesterday’s man, trying to relive old glories. A kind of Tony Blair in fact, unable to let go of the party he led for a decade in the last century.

Labour will still try to portray him as a politician of the past. But if he has any lack of confidence in his ability to remake himself, I couldn’t find it in Perth. Salmond is hugely self-confident, but there has always been a brittleness and a bumptiousness behind the intelligence and political wit. But he seems to have left a lot of that behind in his wilderness years. It has been replaced by a kind of seriousness and – yes, I know this will raise howls of laughter – a kind of humility I haven’t seen in the SNP leader before. Plenty of time, of course, to screw it up. The SNP are past masters at snatching defeat from the jaws of victory. They have been much further ahead of Labour before in the polls, only to fall before the finish line. Their policies have yet to be tested in the heat of battle, and some – like the abolition of all student debt – look very expensive.

Moreover, Alex Salmond’s remarkable statement that “the largest party will always have the moral authority” to form the governing coalition, could be a hostage to fortune. No-one seriously believes that the SNP can win a larger number of seats than Labour in May. But the SNP are on their way at last. Come in Mr Salmond, your time is up.