Patterns of post-reform abortion politics: court rulings and counter-legislation in Mexico and the US

Courts have become key venues for resolving disputes over value-laden policies. Yet, conflict often persists after judicial decisions, with actors pursuing counter-legislation to resist verdicts. Focusing on abortion policy, we argue that two features of rulings—their type and their degree of ambiguity—shape opposition actors’ resistance tactics. Whether a verdict validates or invalidates existing state policy determines the goal of counter-legislation: to undermine the ruling’s implementation or hinder its diffusion. Ambiguity regarding future policy determines the room for resistance, with ambiguous verdicts offering more leeway to defy judicial mandates. We illustrate this argument by comparing two near-identical federations—Mexico and the US—where mobilization in the aftermath of court interventions resulted in dramatically different policy trajectories. Our findings highlight how court rulings impact opposition strategies and shed more light on the post-reform stage as a crucial phase in determining the fate of liberalizing reforms.