THE by-election result in Glasgow's North East ward is a rarity by recent standards, because the SNP were comfortably ahead on first preference votes in spite of the fact that Labour had topped the poll in the ward at the local elections in 2022.
To put that in perspective, in 2022 the SNP were still the ascendant force in Scottish politics, and had a national lead over Labour of more than 12 percentage points. Without doubt, then, the SNP have just captured territory that is unusually favourable for Labour.
If the pro-SNP swing in the by-election were to be replicated across Scotland, the SNP would be a whopping 20 points clear of Labour – a bigger national lead than even the opinion polls have been suggesting.
The result is also a useful benchmark in another way, because it can be compared with a previous by-election that was held in the ward as recently as last November, at a time when Labour's decline was already well underway.
Not only has there been a hefty 4% swing to the SNP since then, but the SNP's own vote share has recovered by two percentage points.
On the face of it, that would be consistent with the SNP's national popularity having risen over the last four months, and Labour's vote having continued to slide. However, a touch of caution is called for, because voters are often known to punish any party that is identified as having caused an "unnecessary" by-election, and in the North-East ward Labour may have been perceived as the culprit The vote was triggered by the disqualification of the winning Labour candidate from the November by-election.
But Thursday's other Glasgow by-election, in the Southside Central ward, offers hope that the SNP's victory in North East was not just a fluke brought about by special circumstances.
Technically Southside Central produced another SNP gain from Labour, although in this case the SNP had been narrowly ahead in the ward in 2022, so to win all they needed to do was stand still. And, indeed, there was practically zero swing, a result consistent with the SNP having surged back to their dominant 12-point national lead of three years ago.
If averaged out, the two-by-election results imply an even bigger lead of 16 points. That would put the SNP on course for a massive landslide majority among Scottish seats in any Westminster General Election.
If the SNP's position relative to Labour has indeed improved markedly of late, what might the explanation be? One obvious point about these by-elections is that they were the first electoral test since the UK Labour Government announced devastating cuts to benefits payments for some of the most vulnerable people in society.
If that was going to trigger a backlash, the effect might be expected to be felt most powerfully in Glasgow wards containing areas of deprivation where the loss of a safety-net will be met with genuine terror.
So it's just conceivable we may be seeing the first indications that the "Liz Kendall factor" has sent Labour into an even deeper hole than they had previously found themselves.
Another possibility is that the ongoing Reform UK bandwagon in Scotland is taking a disproportionate toll on Labour. However, that is only relevant to the result in the North East ward, where extraordinarily Reform took almost one-quarter of first preference votes.
After the Reform candidate was eliminated, most of his votes did not transfer to other parties – but of those that did, almost twice as many transferred to Labour as to the SNP. That indicates a hefty chunk of Reform voters may have been grabbed from the traditional Labour support.
By complete contrast, Reform suffered an embarrassing flop in the Southside Central ward, finishing behind the Greens and even the SSP. That can perhaps be explained by the ward's more cosmopolitan demographic mix.
But because the Greens polled so well, there's a valuable opportunity to see how the SNP are performing in the transfers from Green voters, two years on from the catastrophic breakdown in relations between the two former coalition partners.
Encouragingly for John Swinney, 71% of Green transfers went to the SNP. If the Greens do not put up candidates in many Holyrood constituency races next year, that may mean that opinion polls are understating the SNP's true advantage over Labour, and that the SNP are firmly on course for a really big haul of seats in the Scottish Parliament election.
