Parties of the extreme Right have experienced a dramatic rise in electoral support in many countries in Western Europe over the last two and a half decades. This phenomenon has been far from uniform, however, and the considerable attention that the more successful Right-wing extremist parties have received has sometimes obscured the fact that these parties have not recorded high electoral results in all West European democracies. Furthermore, their electoral scores have also varied over time, with the same party recording low electoral scores in one election but securing high electoral scores in another. This book examines the reasons behind the variation in the electoral fortunes of the West European parties of the extreme Right in the period since the late 1970s. It proposes a number of different explanations as to why certain parties of the extreme Right have performed better than others at the polls and it investigates each of these different explanations systematically and in depth.