Binaries dominate Western classification systems, and those that fall in between binary terms are often subject to discursive erasure. This thesis examines the category bisexual as a hybrid of the binary set heterosexual/homosexual, and argues that the cultural erasure of bisexuality is a function of power structures enabled by the binary system of categorization of sexual identities. Defining binary terms is a deliberate process enacted by dominant groups to establish difference and thereby maintain separation and differential distribution of resources and power in society. Marginalized groups also participate in this discourse, at times refuting it, but at other times bolstering it in efforts to claim legitimacy and resources. The hybrid threatens binary logic by calling into question the reality and sustainability of the two purported categories; the hybrid expresses the fluidity of identity and the instability of dichotomous terms, suggesting that the differences between groups are neither essential nor cause for differential treatment of persons based on such categorization. A comparative exploration of biracial as a hybrid of Black and white bolsters this argument, as commonalities between discourses on bisexuality and mixed race illuminate the operation of binary categories and the way in which they maintain hierarchical systems that privilege some groups and oppress others. This work sheds light on the ways in which binaries function in these two realms, the sexual/gendered and racial, thereby increasing the utility of identifying and deconstructing binary categories as an analytical tool for understanding and improving the social world.