There’s an old saying in politics, that if you’re not a socialist when you’re 25, you have no heart, and if you’re still a socialist when you’re 35, you have no brain.

It’s a cute turn of phrase, but it has some data to back it up. People tend to become gradually more economically conservative as they age, because they become more dependent on climbing the employment ladder, on efficient public services, on economic and financial stability.

In Scotland, though, we have long been told that we are different; a left-wing country immune to these political norms.

It is perfectly understandable that this perception has developed, particularly since devolution. The Scottish Parliament, in comparison to other European parliaments, is very light on elected politicians from parties of the centre and centre-right. Even in the countries to which our political establishment likes to compare us, such as Ireland and the nations of Scandinavia, the prevalence of centrist and right-sided politicians is far greater.

In Norway’s Storting, for instance, not far off 60 per cent of its members are from parties identifying as centrist or to the right, a similar proportion to the Riksdag in Sweden and Finland’s Eduskunta.

The prevalence of the centre and right is a little less in Denmark’s Folketing and the Althing in Iceland (just under 50 per cent), and is over 40 per cent in the Dail, the parliament of our nearest neighbours in the Republic of Ireland.

In Holyrood, though, where Scotland’s Tories are the only party identifying as centre-right, and even including the Liberal Democrats as centrist (which is debatable), only around one in four MSPs are from this ideological home.

So when we are told that left-wing politicians equals left-wing voters, as we have been throughout devolution, the composition of our Parliament has demanded that we offer the thesis some credence.

Frankly, though, I have always considered it the unadulterated nonsense of activists and elitists trapped in an echo chamber, in which desire is synonymous with reality. Fortunately, we now have the evidence to support the critique. On Monday, Kate Forbes holed the left-wing theory below the waterline.

Read more: John Swinney’s most important job may be yet to come

Ms Forbes’ campaign, once it got past the initial focus on her religion, took on a laser focus on economic growth. It is important to say that this would not and should not usually be considered to be a right-wing outlook. Scandinavians, for instance, both social democrats and free-market liberals, see it as axiomatic that in order to redistribute wealth you have to grow it first.

It was, nonetheless, a change in a party and a country which has become unencumbered by economic reality. It went down like the proverbial bucket of cold sick. One couldn’t read a newspaper column about the leadership election without reading comments about the existential danger of a "lurch to the right", and about how the party would lose its activist base in the click of a finger.

Just under 48 per cent of that same activist base then voted for it. The party has struggled to cope in the wake of that platform –  that appeal to put economic growth and public service reform at the heart of the agenda –  garnering nearly half of the votes in the leadership election. 

That this is not merely a bad dream has shaken and shocked the SNP. Not only is economic liberalism alive and kicking in Scotland; economic liberalism is alive and kicking in the SNP.

For the moment, though, this insurgence in the SNP is back in its box. Humza Yousaf won from the left, picked a Cabinet from the left, and will govern from the left. This is perfectly sensible inside the Holyrood parliament building – life there will be a breeze. 

But outside that building, perhaps not so much. In 2014, hundreds of thousands of soft centrists chose the devil they knew because they saw the Yes campaign as long on economic fantasy and short on economic reality. Little has changed, and indeed Ms Forbes was correct to diagnose a deteriorating relationship with small and medium-sized businesses, the backbone of our economy and our tax base.

So, this wide and deep hunger for centrism still lacks a vehicle capable of carrying it to government.

Read more: Why Yes camp should meld the best of Yousaf and Forbes

It is not the Tories. The policy platform of Scotland’s Conservatives is a perfectly viable centre-right agenda, but the party is deficient in two fundamentals which cast a shadow over everything else. 

The first is that they are, in their DNA, a devo-sceptic party. This simply doesn’t play beyond the 10-or-so per cent of people who want to see Holyrood abolished. It hasn’t worked, it can’t work, it won’t work, and it pushes pro-devolution centrist Scots to the SNP, or even to Labour.

The second is that the party emotionally and stubbornly refuses to cut its ties with its Westminster mother, despite all available evidence showing the ceiling it places on their support amongst those typical Scots who don’t love the UK but don’t want to leave it either.

Indeed, so impotent are the Scottish Tories that it is fair to say Ms Forbes has done more to advance the cause of economic liberalism and public service reform in the last six weeks than the Tories have done in the last 16 years. This is not a criticism of Douglas Ross and his predecessors as Tory leader; it is simply a matter of political reality that the job comes with baggage too heavy for even the best politicians to carry.

So, what now? We know where the gap in the political market is. It is in that centrist position, understanding that wealth can only be distributed once it is created and that pouring money into unreformed public services makes them worse, not better. It is in a party which speaks the language of entrepreneurialism and progress. 

This is a gap worth filling –  if Scotland is anything like our Irish or Scandinavian peers, government awaits. 

Could it be filled by a returning Kate Forbes, after a second crack at leadership further down the road? Perhaps.

Could it be Douglas Ross, if he breaks the chains? Maybe.

Could it be Anas Sarwar, after an injection of post-2024 Starmerism? Who knows.

It will be someone. Politics is a market. Gaps get filled.

Andy Maciver is Founding Director of Message Matters and Zero Matters