SUSPEND disbelief for a moment, if you will. Imagine that in the early hours of December 13 we learn that Jo Swinson, leader of the Liberal Democrats, has clung onto her East Dunbartonshire constituency. So far, no massive act of imagination.

But not only has she retained her seat, her party has overnight turned the British political landscape from a patchwork of blue, red and yellow into a cornfield of LibDem gold. Confounding every pundit’s expectations, and perhaps Swinson’s private expectations too, suddenly she is our new prime minister.

Would she be just for Christmas, or would she have lasting power? Might she turn out to be all mouth and no trousers, a one-election wonder whose vaunting ambition far outstripped her ability? Or does Swinson have the qualities to become a remarkable statesperson, in the mould of Nicola Sturgeon or Jacinda Ardern, say or even Angela Merkel?

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At this point, all that can with certainty be said in her favour is that she is a grafter who, by a combination of charisma and conviction has already reinvigorated her party. Above all, this mother of two from Milngavie has put no limits on what she hopes to achieve. From the outset, Swinson, who is a graduate of the London School of Economics and married to former LibDem MP Duncan Hames, has had her eye on Number 10. Depending on your view, this makes her either an optimist or a fantasist.

The tarnished reputation of Coalition Clegg is still vivid in the collective memory, yet it is to Swinson’s credit that she is undaunted about that shamefully lost opportunity. She is not just willing but champing at the bit to show that with its anti-Brexit mandate, a LibDem government can restore the country to economic stability and harmonious sanity, working in fruitful partnership with Europe and in so doing helping to maintain peace across the continent – this being arguably the most important function of our European membership.

The confidence Swinson exudes can be abrasive since she allows no room for doubt. But what politician ever admits to uncertainty? It would be like a priest denying the existence of God. And why would anyone take on this role if they did not aspire to become one of the big beasts in the jungle?

No wonder Swinson is furious at not being included in the ITV debate between Boris Johnson and Jeremy Corbyn. She might be right in concluding there is sexism at work, but in this instance, it’s equally likely to be the patronising assumption that the LibDems – like the SNP, Plaid Cymru and others – are a negligible factor in the election outcome. Come mid-December they will be useful only as guy ropes to support whichever of the two leading parties wins.

HeraldScotland:

Entering the fray at a time when women are leaving Westminster in shoals, Swinson evinces no fear. Gutsiness is one of her trademarks. And how important that will be, should she take the prize. The jury is still out on whether Theresa May was a victim of gender prejudice, compared to the loyal old boys’ network that buoys up her non-stick successor. What is irrefutable is that while an atmosphere of machismo still predominates at Westminster, in its day-to-day business Parliament is no more sexist than other professions. Arguably it’s less biased, because its affairs are conducted in a public arena.

Even so, it remains a tougher job for women, especially those who have a young family. Long and unpredictable hours make even the most careerist or conscientious feel pangs of maternal guilt. Should Swinson become Prime Minister, she will be the first leader to step into Number 10 as the mother of a toddler and primary school-age child. To date, such a scenario is the stuff of the Danish TV series Borgen, not British reality. From what I have seen of this indefatigable and steely 39-year-old, however, I have no doubt she would take that in her stride.

In part, this is because her other distinguishing feature beyond courage in taking on a very male establishment is the height of her aspirations. Unlike many talented women who hesitate to reveal naked ambition, Swinson is refreshingly open in stating her goals.

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Despite coming from Glasgow – no small advantage in the political bear-pit – she does not have the innate sense of entitlement of a Clegg, Johnson or Cameron. Like many state-educated high-flyers, her confidence has been self-built. As a result, she is better placed to cope with knocks and set-backs than those who have glided into the House of Commons like swans.

Swinson shares this self-made spirit with Maggie Thatcher, but there the similarity ends. Compared with Thatcher, what she lacks thus far is a long-sighted and judicial political perspective. This was plain from her first day in the job, when she ruled out any negotiation with Labour to install Jeremy Corbyn as a temporary unity government leader.

It was a worrying early and dangerously cast-iron veto, and in retrospect might be the symptom of a deep-seated flaw. It is one thing to have clear principles, quite another to be so stubborn that pursuit of a party-line becomes more important than the well-being of the country.

That evidence of pigheadedness is the most troubling aspect of Swinson’s performance so far. Inflexibility is a route to disaster, as May’s pitiful tenure showed. A prime minister ought never to abandon their principles, but these must be governed by something more profound and subtle than electioneering dogma. Perhaps, of course, Swinson’s doggedness is a response to Clegg’s weathervane performance. Perhaps, like those who are secretly not as assured as they appear, it is a tactic intended to convey strength.

In the unlikely event of Swinson taking the helm, she must remain steadfast but flexible. A touch of urbanity would go a long way to mellowing her stridency and toning down the almost-messianic zeal with which she is heid-banging the door of Number 10.

But once over the threshold could she make a good fist of it? You need only consider the present incumbent and his closest rival to suggest that she can. The most we can probably say at this point is that she – surely! – could not do worse.