ABSTRACT
This chapter addresses how changing political opportunity structures change the demographic profiles of social movement activists. It suggests that there are two mechanisms through which changing political opportunity structures affect activists' demographic profiles. First, the changing political opportunity structure serves as a filtering mechanism that draws activists with different biographical backgrounds into movements during different historical phases while filtering out others with different profiles. Second, changing political opportunity is a catalyst for a shift mechanism, whereby certain types of activists leave a social movement to take advantage of new opportunities in another sector—electoral politics in the case of Taiwan—while new types of activists are drawn into the movement. The chapter considers the duration of activists' commitment to social and political action and the factors that influence their decision to remain in or leave a movement to understand the relationship between historical forces and changing movement demographics.
