The concept of political opportunity structure is in trouble, in danger of becoming a sponge that soaks up virtually every aspect of the social movement environment – political institutions and culture, crises of various sorts, political alliances, and policy shifts. As Tarrow notes (1988: 430), “Political opportunity may be discerned along so many directions and in so many ways that it is less a variable than a cluster of variables – some more readily observable than others.” It threatens to become an all-encompassing fudge factor for all the conditions and circumstances that form the context for collective action. Used to explain so much, it may ultimately explain nothing at all.

Part of the problem is that analysts use political opportunity structure to serve a wide variety of functions, and define it accordingly. Scholars who want to explain the emergence and influence of a movement over time use it as a set of independent variables, to describe dynamic aspects of the political environment that change to allow or encourage the emergence of challengers (e.g., Jenkins and Perrow 1977; McAdam 1982; Meyer 1990, 1993a). Others who want to compare the development of similar movements in different nations, states, or cities use political opportunity structure as a holder for intervening variables such as institutional structures or rules of representation (e.g., Amenta and Zylan 1991; Eisinger 1973; Kitschelt 1986; Tilly 1978).