ABSTRACT Why do white nationalist organizations (WNOs) focus attention on the issues they do? I draw from social movement studies, organizational studies, and social psychology to explain why WNOs shift attention over time to one particular grievance domain: borders- and immigration-related issues. I propose a cognitive-environmental theory of attention shifts and argue that WNOs are more likely to shift attention to borders and immigration when there is a grievance-validating external shock that is likely to be interpreted as a threat. Using a unique dataset of digitized WNO literature between 1980 and 2008 and a combination of computational text analysis and panel models, I find that white nationalist organizations in this sample were more likely to shift attention to borders and immigration when there was a high number of non-right-wing terror threats or attacks in the U.S. in the previous year relative to the size of the organization’s non-Hispanic/Latinx community. I conclude with implications for work on attentional selection and the evolution of discursive fields.