It’s a message that’s served her extraordinarily well over recent years. Why wouldn’t she stick to it? Scottish Conservative Party leader Ruth Davidson has dragged her party from the political doldrums by focusing her political might on opposition to a second independence referendum.

While First Minister Nicola Sturgeon continues to threaten a referendum that she has neither the power to call nor the political momentum to win, Davidson remains unshakeable in her belief that indyref2 would be a mistake.

And polls continue to show that a majority of Scots share her view.

Ruth Davidson waves to Scottish Conservative delegates after delivering her keynote speech at the Aberdeen Exhibition and Conference Centre. Picture: Jane Barlow/PA

So, it was hardly surprising when, during a speech to her party’s conference in Aberdeen yesterday, Davidson returned to that central message.

The country, she said, has had enough of the SNP “agitating for independence”. There is nothing, she added, to prevent Scotland making progress, now, as part of the United Kingdom.

As she restated her desire to become Scotland’s next first minister, Davidson said that, if the Scottish Tories win the 2021 Holyrood election, she will not “use every engagement with the UK government as a chance to sow division”. Her guarantee was this: if she succeeds Nicola Sturgeon in two years’ time, there will be “no more constitutional games and no more referenda”.

To the most committed unionist, this restatement of her pro-UK credentials will have played well, I’m sure, but I wonder whether Davidson – or, indeed, any leader of the Scottish Conservatives – will be able to maintain any kind of political momentum without looking at the constitutional settlement.

When Davidson became her party’s leader in 2011, she did so as a liberal, centre-right Tory. Attracted to the party by then leader David Cameron’s modernising project (remember that?), Davidson was clear from the start that not only was she not a Conservative of the old school but she had nothing but contempt for the right-wing duffers and Little Englanders who make up much of the party’s membership south of the border.

It may have seemed that the Scottish Tories had long since been fatally wounded, but Davidson breathed new life into her party and persuaded a substantial number of voters – who would previously have viewed putting their cross beside a Conservative candidate’s name as an act of heresy – that they could, in fact, back her without precipitating the fall of the sky.

It is undoubtedly the case that Davidson is a talented politician with a quick wit and easy way with voters, but even her most enthusiastic admirer would have to concede that the Scottish Tories’ rebirth – which saw them go from a third place irrelevance at Holyrood to become the main opposition party after the 2016 election – is not entirely down to her abilities. The SNP’s decision to continue to threaten another referendum, despite losing by a substantial 55-45 in 2014, has been massively helpful to Davidson. The nationalists’ monomania has given her something to react against.

It may be that, even if the SNP had ruled out indyref2 for the foreseeable future, Davidson’s star would have risen anyway, but there can be no question that the constitutional question provided her with a political raison d’être.

The world has changed since Davidson went on maternity leave six months ago. Those unreconstructed right-wing Tories that she so disdains now have the wind at their backs. Theresa May – “Big T” as Davidson tried to style her during interviews in the aftermath of the 2016 EU referendum – may have been a fellow Remainer, but it is the Leavers among the Tories at Westminster who have been directing political traffic.

As the old Tory right rises, Davidson has some presentational problems to address. And things are going to get more difficult.

It may have been possible, while Cameron was prime minister, for Davidson to present herself as a Tory moderniser, a key player in a movement that was shifting her party from the right towards the centre.

But, after defeat for the Remain campaign cost Cameron his job almost three years ago, Davidson has looked more isolated. Yes, she is still liberally-minded with an instinct to modernise and make the Conservatives more appealing to Scottish voters, but her colleagues at Westminster have never looked more unreconstructed.

When May goes, as she has promised she will, favourites to succeed her as Tory leader and, thus, prime minister include such “characters” as Boris Johnson, Jeremy Hunt and Dominic Raab. Can you imagine Davidson forming a pally double-act with any of them? I can’t.

If Davidson’s message is that she represents a new kind of Tory Party, the presence of any of those men in 10 Downing Street will fatally undermine it. Davidson rejected a bid by Johnson to attend this weekend’s conference in Aberdeen. She is hardly about to change her view of him (short version: he’s completely self-interested and untrustworthy) any time soon.

Those Scottish voters who backed the Tories because they believed Davidson represented a fundamental shift in the party may feel that, for example, prime minister Raab shows that nothing has really changed.

How, then, can she continue to build on her current success without being brought low by associations with the Tory-right?

Perhaps the answer lies in the constitutional question.

When he stood against her for the Scottish Tory leadership, Murdo Fraser proposed the creation of a new centre-right party which would be independent of the UK Conservatives. That didn’t fly with party members but Fraser continued to talk the language of real change, suggesting in 2014 that the UK might be reorganised on a federal basis.

Davidson should examine Fraser’s proposals carefully. Standing against the break-up of the UK remains a reactive position. If Davidson is ever to take control of the debate, she will have to tell us what she will do as well as what she won’t. The maintenance of the United Kingdom under a new federal arrangement might just spike the nationalists’ guns.

If Ruth Davidson is to navigate the twin perils of the SNP and the Tory right, leading the argument on a new constitutional settlement might represent her greatest chance of success.

Euan McColm: Now toxic Tories are back, scourge of indyref2 won’t cut it