Why do left-of-center governments with redistributive goals, facing the same commodity boom, adopt opposite strategies for taxing export agriculture? This chapter motivates the comparative inquiry and situates it within work on business politics and the economic and institutional consequences of natural-resource dependence. It advances the book’s central claim that windfall rents do not translate mechanically into policy; rather, outcomes are filtered through agricultural interests’ institutionalized political resources, which reflect the interaction of the territorial footprint of production, patterns of party competition, and the design of domestic political institutions. Theoretical expectations follow: where representation is dense and partisan linkages robust, agricultural interests are more likely to fend off redistributive threats; where political resources are thin, defensive mobilization occurs through extra-institutional channels and rent appropriation becomes more likely. Treating the 2000s price surge as a critical conjuncture, the chapter specifies permissive and productive antecedent conditions that tilt the playing field prior to the international price shock. It then previews a most-similarcases comparison between Argentina and Brazil and a mixed-methods strategy combining field interviews, analysis of official documents, and multivariate tests embedded in mechanism-focused, within-case process tracing.