More or Less Vulnerable?

West European party systems have undergone profound changes, one of the most obvious being a marked decrease in vote share going to the mainstream parties whose domination of electoral politics used to be taken for granted, along with an increase in votes going to more radical, populist contenders—most (but not all) of them on the anti-immigrant right. These two changes are widely assumed to be linked. Yet the potential impact of the populist radical right on the electoral performance of (western) Europe’s other party families may well be uneven. We use European Election Study survey data to explore which parties (and party families) might be most vulnerable to seeing their voters defect to the populist radical right. We find that, although it has become commonplace to observe that it is the social democratic centre-left which is most vulnerable in this respect, it is actually centre-right parties which, at this point anyway, would seem to have most to lose. But they are not alone: interestingly, the voters of radical left parties are also vulnerable to the appeal of the radical right.