It is difficult to overstate how poor the SNP’s performance was in June’s general election.
The party’s share of the vote fell from 50.0 per cent to 36.9 per cent, mislaying half a million supporters in just two years. The party lost 21 seats, a staggering 38 per cent of its parliamentary party.
The SNP should have foreseen their difficulties – there were clues in the May 2017 local elections that the party was losing significant ground, their vote share was only 38 per cent in May 2017 once you adjusted for independents – but their problems have more structural causes.
First, the SNP’s diverse voting coalition has begun to fray. The tension between its traditional “Tartan Tory” rural heartlands in North East Scotland and former Labour voters in urban and central belt seats mean that the 2015 SNP voter group was always going to be difficult to hold together.
Having swallowed the Labour party whole in 2015, it finds itself stuck now in a pincer movement between a Conservative party more appealing to Unionists and Brexiteers alike and a Labour party that has found its voice again amongst those more inclined towards Scottish independence. It lacks a demographic or political home and risks collapsing as quickly as it rose.
There are three key elements to the SNP’s disastrous performance.
The 36 per cent of 2015 SNP voters that voted Leave in the 2016 EU referendum were taken entirely for granted by the party. Unwilling to simply swap the yoke of Westminster for that of Brussels they left the SNP in large numbers for Ruth Davidson’s Scottish Conservatives.
These SNP-Leavers joined other recent Unionist defectors from Labour and the Liberal Democrats who found the Tory constitutional clarity on Scottish independence appealing.
Secondly, across the UK, Labour’s “youthquake” delivered surprising levels of support for the party. This was especially true in Glasgow and Edinburgh; particularly when comparing the Labour 2017 general election performance (27 per cent) with the Scottish parliament election the previous year (19 per cent on the constituency vote).
It’s clear that younger voters, and those more inclined to want an independent Scotland defected to Labour in large numbers during the general election campaign. The Tory surge was, to a degree, expected. The return of Scottish Labour less so. Both together lead to losses that SNP politicians and advisors could scarcely believe on election night.
Thirdly, a large number of 2015 SNP supporters simply stayed at home this year. Areas with the highest SNP vote share in 2015’s general election experienced the biggest decline in turnout in 2017.
Unfortunately for Nicola Sturgeon, the challenge facing the SNP could get even more acute in the future. The average majority for an SNP seat has fallen from a comfortable c.10,000 in 2015, to a marginal c.2,500 for the 35 seats it currently holds. Its 2015 super majorities across Scotland have been decimated, and almost its entire parliamentary party now hold marginal seats. 2017 could have been even worse for the SNP: if just 4,800 people had voted differently in Scotland the SNP could have lost 36 seats, not just 21.
If the SNP, the Scottish Conservatives and Scottish Labour all converged towards 30 per cent, the SNP would win just six seats, The Scottish Conservatives 18, and Scottish Labour 30.
The first past the post system which so richly rewarded the SNP in 2015 could punish it badly in the future. The SNP Westminster parliamentary contingent would in such a 30/30/30 scenario be smaller (all other things behind equal) than even the Liberal Democrats, the DUP and Sinn Fein.
As Ukip – another nationalist party – would attest to, a meteoric rise can be followed by a fall which is almost as dramatic.