The National:

ETTRICK, ROXBURGH AND BERWICKSHIRE

Winner in 2016: John Lamont (Conservative)

Winner of 2017 by-election: Rachael Hamilton (Conservative)

OF the many extraordinary victories in the SNP’s Westminster landslide, arguably the most impressive of all was Calum Kerr’s win in the normally unfavourable territory of Berwickshire, Roxburgh and Selkirk, right on the Border.

But to achieve that required a considerable slice of luck – he took just 37% of the vote, and that was only sufficient due to the Liberal Democrats retaining a big enough minority of the Unionist vote to keep the Tories down to 36%.

Essentially Kerr caught a sweet spot as the LibDems were on their way down and the Tories were on their way up. The window of opportunity soon closed – in 2019 Kerr took a bigger 39% vote share but still lost to the Conservatives’ John Lamont by a significant margin.

In the nearest equivalent Holyrood constituency, the window of opportunity never opened up in the first place, because Lamont and the Tories gained Roxburgh and Berwickshire direct from the LibDems as early as 2007.

The SNP remained in a very distant third place, in spite of the fact they had narrowly come out on top in the national popular vote for the first time. That perhaps gives an indication of just how well the SNP need to be doing nationally before they can expect to be competitive in this part of the Borders.

READ MORE: Nicola Sturgeon 'quietly confident' she will beat Anas Sarwar in Holyrood election

Even in 2011 when they were winning an overall majority, the SNP were 18 percentage points behind the Tories in the redrawn Ettrick, Roxburgh and Berwickshire seat, although they did at least manage to break the traditional local duopoly by overtaking the LibDems and moving into second place.

They enjoyed a further 5% increase in their vote share in 2016, but by then they had to contend with the national Ruth Davidson surge, which meant there was actually a net swing from SNP to Tory in the constituency. Lamont’s already healthy majority increased to almost 8000 votes.

The constituency had become safe enough for the Tories that there was no great risk in Rachael Hamilton resigning her South Scotland list seat to contest the by-election triggered by Lamont’s switch to Westminster in 2017. She secured a comfortable win over the SNP’s Gail Hendry, sister of Alex Salmond.

The Tories’ majority increased, both in terms of actual votes and in percentage terms, meaning that the SNP require a daunting swing of more than 12% to gain the seat this year.

It’s very hard to imagine that happening without some kind of external help – in other words without the Unionist vote being split due to a LibDem or Labour surge. This is unlikely, although the Labour candidate is the well-known figure of Ian Davidson, former MP for Glasgow South West.

He was born in Jedburgh, and is making a third attempt at winning in his home patch after standing for the Westminster constituency in 2017 and 2019.

On the latter occasion he took just 4.7% of the vote and lost his deposit, but understandably refrained from trotting out his delightful catchphrase about “bayoneting the wounded”.

The likelihood is that Hamilton and the Tories will once again take a large enough share of the Unionist vote to make it essentially impossible for the SNP to win.

Indeed, it may even be impossible in a very literal sense, because the Tories could well exceed 50% of the vote for a third time in a row.