Climate clubs, or “minilateralism,” are increasingly advocated as a way to move global climate governance forward. Minilateralism supposedly carries structural advantages that facilitate effective climate governance. Some have cautioned, however, that climate clubs lack political legitimacy, commanding little domestic public support. Consequently, small coalitions might not always be politically feasible, even if they could deliver substantial mitigation. Design features like the emission share regulated, commitment structure, club goods, and sanctions against nonmembers could help mitigate this deficit. I report results from conjoint experiments testing these propositions that were conducted with nationally representative samples in the United States and India. The findings indicate that minilateral approaches per se tend to receive low public support, but that support can be increased by certain configurations of design elements, especially through a combination of club goods for members and sanctions against nonmember countries. Climate clubs therefore need careful institutional design to be politically feasible.