Tarrow is a leading expert on new social movements and, more broadly, the phenomena of contentious behaviour.
[1] Tarrow's five elements of political opportunity structures includes: 1) increasing access, 2) shifting alignments, 3) divided elites, 4) influential allies and 5) repression and facilitation.
In the book, Tarrow tries to explain the cyclical history of social movements (visible in the form of the protest cycles).
He also shows how movements can affect various spheres of life, such as personal lives, policy reforms and political culture.
In that book he also lists four prerequisites of sustainable social movements: 1) political opportunities, 2) diffuse social networks, 3) familiar forms of collective action (also known as the Charles Tilly's repertoire of contention), and 4) cultural frames that can resonate throughout a population.