HE is the nearest thing that once mainstream Tories have to an elder statesman. William Hague, the one-time teenage prodigy who flopped as a youthful Conservative leader, has aged well.

Still just 62, the former foreign secretary now dishes out doses of usually sage advice from the benches of the House of Lords and the pages of The Times.

Last week Baron Hague of Richmond – albeit with self-declared humility – tried to have his say as Scotland’s political partisans noisily spat, yelled and cried about the new SNP leadership.

Unionists, the peer cautioned, should not be complacent. Because the SNP can still count on sizeable chunk of the electorate. How come? Because, Lord Hague argued, “Scottish nationalism is an essentially populist force and can enjoy strong support irrespective of its actual policies or achievements”.

The old Tory is not the first to call the SNP populist. Nor will he be the last. True, he made a better, more articulate, stab at making the case than most.

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“Scottish nationalists have much more in common with the Leave campaign or other largely populist movements than they would like to admit,” he argued. “They blame a distant authority, in this case in London, for all problems; they advocate a simple and sweeping solution, in this case independence, without credible plans as to what to do afterwards.”

Lord Hague even preambled his argument by acknowledging that his own party, back when he led it, was seen as an “English elite” in Scotland.

And what is the most common classic definition of a “populist”? Well, it is a politician who claims to represent a virtuous but ill-defined “people” against a wicked “elite”.

Increasingly, as Lord Hague implies, the word is also applied to demagogues who insist there are easy answers to complex modern problems.

He is no doubt thinking of the periodic bouts of nationalist rhetoric suggesting independence is the magic cure to all Scotland’s ills.

So is the SNP populist? Maybe. Kinda. A bit. Sometimes. But “essentially so”, as Lord Hague asserts? I am not sure that is entirely fair. But it is a claim worth exploring.

How we answer this question rather depends what we mean by the p-word. And even political scientists do not exactly agree about what “populism” is.

The Herald: The pressure for independence is unlikely to disappearThe pressure for independence is unlikely to disappear (Image: FREE)

Is it an ideology? Or just a style? Is it a defining characteristic of entire parties? Or just a tactic politicians turn on and off, a rhetorical flourish they can dial up or down?

Or, somehow, all of the above?

So how would you test the SNP for “populism”? Well, you could take a simple definition of the term – most likely anti-elite rhetoric – and count how often this crops up in political pronouncements or manifestos.

This can work, up to a point. But for self-determination movements? Tricky. Why? Because on paper an independence supporter moaning about “Westminster” might look exactly the same as a racist populist from Blackburn doing so.

Sure, Scottish nationalists can be as populist, anti-elite, anti-establishment and anti-politics as anybody else. But spouting about Westminster rule does not necessarily prove that. It just says they favour independence.

Now there is entire school of thought – or more likely rhetoric – that all substate nationalism is just a form of populism.

This is almost an article of faith among some opponents of independence. It is a not uncommon view among researchers and observers who have never lived in a society with competing or overlapping national identities.

It is a point of view, of course. But I think those who conflate separatism and populism – to throw out two usually pejorative words - are going to struggle to understand both concepts.

After all, some independence supporters are more populist than others. So are some self-determination movements.

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There was a sophisticated bit of research done in Spain five years ago comparing the pronouncements of SNP leaders and those of Catalonia’s varied pro-independence parties.

The researcher, Jose Javier Olivas Osuna, found that Catalan nationalists were far more populist than their Scottish counterparts.

“This work helps reject the hypothesis that all nationalist movements are populist,” he concluded.

The academic was not arguing that SNP figures never used populist language. They clearly have done so.

So, of course, have representatives of other mainstream UK parties, especially, I think, Lord Hague’s.

There is another problem with the way many of us use the term ‘populist”. It gets thrown around rather loosely, often as an insult We keep citing the term as we struggle to find a better way to describe a whole series of political parties seen as “backsliding” from democracy, of rejecting the old rules of the western political game: truth-telling, respect for the rule of law, freedom of the press.

So politicians routinely called “populist” include Viktor Orbán of Hungary’s Fidesz, Bibi Netanyahu of Israel’s Likud or Donald Trump and Ron DeSantis of the US Republicans. I can see why.

But we use the same term to describe the fairly clearly left-wing Spanish outfit Podemos or the now waning anti-technocrat, anti-politics crowd in Italy’s Cinque Stelle.

It might be rhetorically pleasing for unionists to lump the SNP in with these mobs. But does it help us understand Scottish nationalism? Nah.

Some SNPers will take offence at a charge of populism. But recent events have showed – at least for those who have not been paying attention – what a broad kirk the party can be. Nationalist politicos can be timid and managerial. And they can also – as leadership candidate Ash Regan demonstrated – pander to the "very online".

There are those who suggest the SNP is not populist enough. They include indyref-watcher Professor Matt Qvortup, who believes a bigger dose of emotional anti-establishment rhetoric would nudge the dial towards Yes.

Lord Hague, I suspect, understands the dangers of such an approach. His party, after all, remains divided between full-fat, added-sugar populists such as Boris Johnson and business-friendly old school conservatives like him.

Are Tories “essentially” populist? Hopefully, not yet.