Contagious parties: anti-immigration parties and their impact on other parties’ immigration stances in contemporary Western Europe

Anti-immigration parties have experienced electoral lift-off in most Western democracies, although the consequences of their victories for real-life policy outcomes have remained largely unexplored. A key question is: do electoral pressures from anti-immigration parties have a ‘contagion’ impact on other parties’ immigration policy positions? In this article, I argue and empirically demonstrate that this is the case. On the basis of a comparative-empirical study of 75 parties in 11 Western European countries, I conclude that this contagion effect involves entire party systems rather than the mainstream right only. In addition, I find that opposition parties are more vulnerable to this contagion effect than parties in government. The findings of this article imply that anti-immigration parties are able to influence policy output in their political systems without entering government.