Abstract Existing research explains variation in trade attitudes by pitting explanations rooted in the foreign part of foreign economic policy, like nativism, against economic beliefs like a commitment to free market principles. But what happens when these factors create significant cross-pressures—how do free market-oriented nativists think about trade? We argue that nativism is a higher-order belief that constrains the relationship between lower-order economic attitudes and beliefs about international trade. We test our argument using representative samples from the United States and United Kingdom. First, we analyze observational data and find a significant interaction whereby nativism moderates the relationship between free market attitudes and beliefs that trade provides national and global benefits. Second, we report results from a survey experiment to show that a message about the long-term benefits from free trade increases support for free trade in both samples. Importantly, we also find that nativist values weaken the treatment effect in the US sample. As long as international relations scholars focus on cultural or economic antecedents on their own, we miss much about how elements in belief systems interact.