NUANCE is frequently difficult to discern in modern political discourse. Partly, I blame the mischievous media. Myself, in short, and my sundry colleagues.

We tend to insist upon absolute certainty from our elected tribunes. She said, he retorted. Condemn, exult, thrill: as long as it is simple and straightforward.

I said that I “partly” blame the mischievous media. It is also down to those voters who say they want clear, precise answers from politicians when, in practice, they often want their own preconceived notions reinforced.

Ditto political parties. All are coalitions of the more or less willing, brought together in pursuit of power or shared objectives.

At a conference, they may dislike or distrust a speaker but they will still cheer to the echo if their particular objective is materially advanced by the address in question.

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It is a bit difficult to gauge such matters in the midst of this hideous plague, when conferences are digital.

But Nicola Sturgeon, who is generally liked and trusted by her party, plainly felt motivated to sound a note of reassuring certainty when she addressed the SNP event earlier this week.

On the topic of a further independence referendum, she said: “Democracy must – and will – prevail.”

People in Scotland, she went on, had “the right to make that choice”. To opt, in short, for independence: which she characterised as playing “our full positive part in the world – as a welcoming, open European nation.”

All clear then? Indyref2 is coming. The only question is precisely when, and that is driven by the pandemic. Once that has passed, the referendum will be instigated and the contest will begin.

For myself, I believe that indyref2 is highly probable. The question of independence is the defining fault line in Scottish politics. When I hear UK Ministers on the subject, I tend to ignore the bombast and listen instead to the interstitial caveats and comments which suggest they are, in practice and over an indefinable longer term, preparing the new ground rules.

READ MORE: Nicola Sturgeon is thinking long – but will the voters give her short shrift?

However, politics is rarely pure and never simple. Nicola Sturgeon knows that applies in particular to constitutional debate. Indeed, her conference address discreetly acknowledged those subtleties to a degree.

The overall tone, of course, was certainty. That was designed simultaneously to assuage her faintly restless party, to defy her political opponents and to convince the citizenry that independence is a real and desirable prospect.

She said further that her party’s manifesto mandate was “unarguable”. That, she invited us to infer, applied to the offer of a further referendum.

Yet she knows empirically that the mandate is not only arguable but is, right now, being vigorously and volubly contested by the Scottish Conservatives, by the UK Government and by others.

It is, indeed, being argued so much that there is widespread speculation, including among senior nationalists, that the issue may yet land in the courts.

Note, however, the full context of Ms Sturgeon’s remarks. She said the mandate was unarguable “judged by any standard of democracy.”

This was not, in short, a simple statement of arithmetical or logical fact. It was rhetoric. It was in itself an argument. She was asserting her own party’s status and challenging her opponents to gainsay that standpoint, implying that, were they to do so, they would be running counter to democracy itself.

However, reverting to arithmetic, the assertion of an irresistible mandate is, in practice, open to question. Look at the figures from the Scottish Parliament elections earlier this year.

Popular support? The SNP gained many more votes than other parties in both the constituency and regional list ballots. But they did not gain an overall popular majority. (The last party to do so in Scotland? The Tories, Westminster election, 1955, different times.)

The SNP took by far the most seats in the constituency section which might count as an unarguable mandate had this been a First Past the Post election. It was not. Including the list outcome, the SNP took 64 seats, one short of a majority.

Ah, but they have an overall lead with the support of the Greens whose manifesto also supported independence.

True, but that is a deal which explicitly falls short of a full coalition and which only emerged several months into the new Parliament, once the First Minister had been reinstalled and the new government formed.

Further, the two parties did not stand on a common election platform, suggesting that one complemented the other. Alex Salmond attempted to do that with his Alba party, proferring unwanted help to the SNP. His party gained just 1.7 per cent on the list.

The Greens stood as rivals to the SNP, challenging them vigorously over their economic strategy and the strength of their commitment to tackling climate change.

It could thus be argued that some of the votes obtained by the Greens represented a degree of disquiet with SNP governance rather than a popular endorsement for their core aim.

To be clear, I am not saying that is a final, substantive or decisive point. I am merely saying it could be argued. The proposition is arguable.

There is, however, a further point which Nicola Sturgeon appreciates only too well. By statute, as presently understood, the Scottish Parliament does not have the power to call an independence referendum because the constitution of the UK, which such a plebiscite would affect, is reserved to Westminster under Schedule 5 of the 1998 Scotland Act.

I write “as presently understood” to acknowledge the possibility that a court might eventually take a different view. For now, the constitution is reserved which is why a Westminster fiat was required in 2014.

Strictly speaking, then, the SNP manifesto this May promised something, a constitutional referendum, which the Parliament being contested, the Scottish Parliament, could not and cannot deliver.

Which is why, in her speech this week, Nicola Sturgeon was careful to stress that she would seek to attain a legal referendum via “co-operation not confrontation”.

To note these various points is not in any way to invalidate Ms Sturgeon’s demand for indyref2: it has momentum. Nor is it remotely to question her own sincerity. She yearns for independence.

It is, however, to note that the “unarguable” will, in practice, be vigorously argued. Until a resolution is reached.

Our columns are a platform for writers to express their opinions. They do not necessarily represent the views of The Herald.