Does Mainstreaming Mean Moderation? Measuring Positional Shifts on Immigration in Sweden

The mainstreaming of the populist radical right (PRR) has become an established phenomenon across the world, notably in European democracies. However, the content and actors driving this process remain debated. On the one hand, academic literature has emphasized the agency of PRR parties to transform themselves and gain integration into the mainstream (Akkerman, de Lange, and Rooduijn 2016). On the other hand, another line of research has focused on the role of mainstream parties coopting PRR positions, a strategy called accommodation (Abou-Chadi 2016; Abou-Chadi and Krause 2020; Krause, Cohen, and Abou-Chadi 2023). Yet we lack a comprehensive assessment of how these processes shape parties’ actual policy positions within a party system. Do PRR parties moderate their positions when mainstreaming? Is there positional convergence with the mainstream? And what causes these policy shifts? This article focuses on the Swedish case and the immigration dimension, taken as a most-likely case to observe convergence, defined here as the combination of PRR moderation and mainstream accommodation. I assess the positional shifts of Swedish parliamentary parties using fifteen years of parliamentary speeches classified with large language models. While acknowledging the limitations of this approach (see, for instance, Baumann et al. 2025; Ollion et al. 2024; Stuhler, Ton, and Ollion 2025), it provides a new and promising way of assessing expressed positions in an extremely granular manner, supported by careful validation metrics. Using a Difference-in-Differences design, the article then examines the causes of the positional shifts identified on the immigration dimension, building on the concept of exogenous triggers developed by Valentim (2024). Contrary to the hypothesis, the article shows that the PRR Sweden Democrats have not moderated their positions on the immigration dimension since their entry into parliament in 2010. By contrast, we observe an important and unilateral process of accommodation by mainstream parties. I show that the 2015 refugee crisis acted as a major exogenous trigger that suddenly prompted mainstream parties to shift toward restrictive positions on the immigration dimension, although this shift appears to differ in magnitude and timing between the left and the right. The article therefore contributes to the growing literature on far-right mainstreaming by emphasizing that moderation does not appear to be a primary component of mainstreaming, even in a case where it was most likely to occur. Building on recent research (Valentim 2024; Wagner and Meyer 2017), it also demonstrates the importance of sudden exogenous triggers in enabling mainstreaming.