Less than three months after the referendum, the SNP has hit new record highs on both the weighted and aggregated measures, which now sit either side of the symbolic 45% level, the share of the Yes vote in the referendum and the SNP's constituency vote in 2011.
The aggregated measure gives figures of SNP 44 (+1) LAB 26 (=) CON 16 (-2) LIB 6 (+1) UKIP 5 (+1) GRN 3 (-2). The electionforecast weighted measure has SNP 46 (+4) LAB 30 (-2) CON 11 (-1) LIB 6 (-1) GRN 4 (=) UKIP 2 (=):
So as we await tomorrow’s Scottish Labour leadership results, the SNP lead over Labour stands at 16 or 18 points depending on the measure, a swing of 20% since 2010. There are two crucial questions – how uniform or otherwise the swing is, and what will happen to the magnitude of the swing between now and May.
We should get some answers to the first question very soon, when Lord Ashcroft publishes his next round of constituency polling. Of course, some seats have to buck the trend otherwise Labour or the Lib Dems would be in negative territory, but those aren’t the interesting contests. Will marginals behave differently to the national picture, and will the SNP’s vote share gains differ depending on whether a Labour, Lib Dem or Conservative MP holds the seat?
The second is much harder to answer because we are in such uncharted territory with the SNP surge that there is no obvious way to model it. On the one hand the move has been so large that some retracement might be expected. On the other hand, the move has come very late in the parliament – Labour is in opposition at both Westminster and Holyrood and oppositions rarely do well in the closing stages. But then, given the unprecedented circumstances, this time might well be different…
For a discussion of the aggregation methodology, please see this piece. You can also view a full list of Scotland posts.