‘Party competition and dual accountability in multi-level systems’ the independence echo: the rise of the constitutional question in Scottish election manifestos and voter behaviour

Since the formation of the Scottish Parliament, the idea of Scottish independence increased in salience and popularity among Scottish voters to such an extent that it now constitutes the country’s defining political cleavage. Given that Scottish politics is increasingly organized around this constitutional question, support for either side of the debate among voters and elites drives political engagement, election turnout and public attitudes to other major issues. Although much popular and academic work has sought to explain the rise of support for independence, few scholars have explored changes in elite behaviour or its consequences for public opinion. From an elite-driven perspective, the increased salience of independence may be but an echo of elite and partisan attention. Developing hypotheses from this approach, we predict that voters identifying with parties developed stronger views on independence following increased attention in parties’ campaigns. We examine these hypotheses by performing computer assisted, unsupervised content analysis of Scottish Parties’ election manifestos. We then use estimates from a structural topic model to predict change in voter support for independence from the British Election Study. The theory and results suggest that increasing salience on alternative dimensions of politics likely closely relates to elite-driven choices in their election campaigns