This qualitative study explored Linguistically Responsive Instruction (LRI) for linguistically diverse Latinx preservice Teacher Candidates (TCs) at a tertiary institution in the southwest region of the United States. To provide an example of preparing TCs to engage in LRI by helping them reflect upon ideological orientations, we operationalized LRI as a series of three reflective tasks--language portraits, ideology trees, and utterance analysis--designed to pose linguistic ideological dilemmas (LIDs) for participants. Findings from multimodal thematic analysis suggest that during the study, engaging in LRI afforded teacher candidates space to explore tensions surrounding broader ideologies in circulation (ideological infrastructures), as well as personal ideological orientations towards themselves, their future learners, and society. These tensions generated dilemmas that caused participants to engage in language and ethnicity gatekeeping in ways that revealed the impact of institutionalized ideological stances toward linguistically and ethnically diverse speakers. Implications include (1) potential ways for faculty and students interested in LRI implementation to interrogate sociopolitical dimensions of language use across disciplines, (2) better understanding of whether and what type of ideological clarity may emerge from LRI in tertiary classrooms, and (3) how LRI might contribute to the disruption of less nuanced approaches to serving linguistically diverse learners in higher education.