The representation of far-right parties in European parliaments has grown exponentially over the past decade. While there are positive signs from Poland and other countries that their rise can be halted, most European countries are still struggling to find an adequate response to far-right challengers. Encouragingly, empirical research into the causes of the success of far-right parties and the prevalence of the socially intolerant attitudes that seem to fuel their electoral rise is multifaceted and interdisciplinary. In particular, research into country-level differences is motivated by the idea of gaining insights into policy choices that might prove effective in countering the spread of intolerant attitudes and the electoral success of the far right. In practice, however, this sprawling field of research has proposed some 70 different social mechanisms (and counting), each of which can claim to partially explain these country-level differences. To better assess the potential of this impressive research, I have conducted a sensitivity analysis that tests each of these mechanisms against each other, using data from 30 European countries over the years 2000 to 2020, in order to identify the most pertinent explanations.
