The SNP's current strengths are its future weaknesses

Unity of purpose. Unyielding internal discipline. A ruthless commitment to pragmatism. Message management. Sticking to the line. With no deviation. Ever. It’s the recipe for electoral success. Or it is right up until the time that it isn’t. As New Labour found, and every party finds out in due course. 

From the outside it seems so easy. To start with, success breeds success, so why not stick with a winning formula. It must seem that way to the Scottish National Party as they head – apparently inevitably and effortlessly – towards another electoral landslide.

Of course it’s not effortless. A lot of polling and testing goes into getting the language and the policies right. And, even with a willing audience, there’s the question of transmission – how do you get new positions out to everyone as soon as they have been developed? But winning is the reward and the prospect of yet another contest ahead binds your party together and unity, pragmatism and success bind the voters to you. An unbroken – and virtuous – circle. 

Yet, as David Chase put it in The Sopranos, “everything comes to an end”.

How? That itself is always hard to predict; politics is when it is working well.

But just as the laws of Newtonian physics prevent the creation of a perpetual motion machine, so the laws of politics prohibit a perpetually elected government. The best place to look for future weakness is in current strength.

Take that message discipline and then think about it. Every SNP Member of Parliament (MP), Member of the Scottish Parliament (MSP) and Member of the European Parliament (MEP) has the same view. Exactly the same view. On everything.

That is arguably true about independence, though clearly not about the economic consequences. It cannot be true about, say, nuclear disarmament. That is a complicated, contested and contestable subject. Ridding the world of nuclear weapons is not simple.

It is implausible, to say the least, that on this issue with its geopolitical importance any group of 120 adults would agree absolutely, let alone 120 politicians. Yet that, apparently, is what all SNP MPs, MSPs and MEPs do. Does this matter? Hardly at all for current electoral purposes. But absolutely if you are a loyal SNP supporter who wishes your chosen party well.

There is winning. And then there is winning too well. The best thing for a government – and a country – is an opposition that can keep them honest and on their toes. The worst thing is the feeling that you can get away with whatever you want. It leads to lazy thinking and sloppy action.

It happened to the Tories under Thatcher with the poll tax. It happened to New Labour under Blair with civil liberties. In the end, you can only go so far – the voters will always pull you back into line. 

Will the SNP under Nicola Sturgeon go too far? Of course they will, they’re only human. In which specific area? It’s hard to tell at the moment, but the fatal flaw is clear enough – the dislike of dissent.

On internal party management that may not matter, though the current crop of SNP ministers are far less impressive than the teams that Alex Salmond assembled –  a consequence, one feels, of the younger generation growing up under control freakery. But it leaves policy unscrutinised and that’s where the slip will come. Debate distils wisdom. Lack of it does the opposite. The thing about difficult social policy problems is that they are, well, difficult. And eventually rhetoric – however uniform – is no substitute for results.