A hallmark of sociolinguistic research is its careful attention to various forms of linguistic heterogeneity on the one hand, and a consideration of the political implications of this heterogeneity on the other. For nearly four decades, John R. Rickford has been a leading scholar on each of these fronts. Rickford’s vast body of work demonstrates a consistent commitment to the interrogation of assumptions about the presence, absence, and nature of linguistic heterogeneity. Insofar as heterogeneity is synonymous with diversity, it is important to consider the relationship between sociolinguistic heterogeneity and public debates about diversity within a globalized and continually globalizing world. By challenging attributions of communicative deficiency on multiple fronts, Rickford’s work teaches us the importance of developing a critical stance toward questions about the relationship between sociolinguistic structures and broader structures of inequality.