In a previous post I discussed the problem of explaining fascism. Let's return to this issue as a topic for historical and social inquiry.
There are clearly a number of different explanatory questions we might have in mind: why did fascist movements emerge and gain popular support in the first three decades of the twentieth century? Why did these movements prevail in several countries and not in others? (This version parallels Skocpol's question about revolutions.) Why did fascist states develop the political institutions they did in Germany, Italy, and Spain? How did fascist states and leaders exercise power? What prevented the rise of powerful fascist movements on France and Britain -- in spite of the presence of ultra-nationalist leaders and organizations?
These are all different questions -- even if there are relations among them. A particularly central question concerns the factors that were conducive to the emergence of extremist beliefs and organizations in certain periods and what factors favored the growth and power of some of these movements. This is a bundle of questions about the conditions that favor collective mobilization and ideological formation on a mass society. It is the sort of research question that Chuck Tilly and other scholars of popular mobilization have been concerned with.
Another set of questions about the course of fascism has more to do with institution building and state formation. Given the goal of creating powerful stare institutions within the general framework of fascist ideas and goals, what institutional and organizational possibilities existed? Here we might refer to the repertoire of mass organization that fascist "revolutionaries" brought to their movement, as well as the historical and practical options that existed. This area of inquiry may provide a basis for answering questions about the particular nature of fascist political institutions.
Finally, the distinct question of why it was that fascist movements and leaders were able to defeat democratic movements and states requires that we identify some of the circumstances that weakened democratic regimes. This may be a wide range of factors: challenges of war, ideological conflict with communists and other critics of the state, and the economic circumstances of the great depression. (These fall in the same category as the circumstances that Skocpol brings forward as being relevant to the success or failure of revolutions.)
It would appear that social scientists and historians have better tools for addressing the issue of successful mobilization than the institutional or causal conditions surrounding seizure of power and state building. Schematically, we might consider a causal narrative along these lines: Conditions that favor fascism include the presence of a marginalized group of young people who are subject to great economic insecurity; an ideology that combines nationalism, ethnic suspicion, and disaffection from established social institutions and values, and a compelling narrative of how and why this group ought to wield power. To this we might add a few propitious international conditions: the threat of war, a widening economic crisis, and a broad view that the modern state isn't up to handling these challenges.
This approach sketches out a view of what might be a basis for an explanation of the rise of fascist social movements. Here we have singled out several causal-social factors that facilitate popular mobilization and the politicization of social movements. What it doesn't yet explain is why and in what circumstances these movements are likely to grow powerful enough to challenge the existing state structure; this remains for another discussion.