As teacher education programs encourage more candidates to pursue bilingual certification, a need exists to improve the ways that preservice teachers (PSTs) are prepared to teach in bilingual classrooms. Research suggests the importance of preparing PSTs in the area of linguistic ideological clarity. Scholars define ideological clarity as an ongoing process through which individuals can critically consider their ideological orientations as well as dominant ideologies that favor those in power, with an aim of becoming agents of change through this process (Alfaro & Bartolome, 2017). This case study sought to understand the opportunities that bilingual PSTs have to develop ideological clarity during a teacher education program, as well as the ways their own linguistic histories might interact with the language ideologies in circulation and development in the program. Drawing from the theoretical lenses of language ideologies (Kroskrity, 2004; Woolard, 1998) and dynamic bilingualism (Garcia, 2009), this study analyzed the ways that bilingual PSTs in the U.S.-Mexico borderlands have come to understand bilingualism and what is necessary to become a bilingual teacher in this context. PSTs reported moments in which their bilingualism was framed in a monoglossic manner during their K-12 schooling, but the teacher education program had afforded opportunities to reframe it through a heteroglossic lens. Participants also described the ways that standardized testing had come to define success for them as bilinguals, both during their K-12 years and again during the teacher education program. Pedagogies implemented during an introductory bilingual education course provided opportunities for PSTs to notice, name, reflect on, and apply ideologies that were evident in their linguistic histories and in current educational practice. The findings of this study indicate ways that ideological clarity may be developed through teacher education, informing the field through implications in teacher education programs, K-12 bilingual education, and state policy. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]