Despite an increasing number of English-language learners (ELLs) in U.S. schools and a trend toward placing them in mainstream classrooms, relatively little attention has been paid to synthesizing and appraising the extant research on how future mainstream teachers are prepared to teach this student population. To shed light on this topic, the article analyzes the limited but expanding body of research on the preprofessional preparation of mainstream teachers for linguistically diverse classrooms. The authors found that between 2000 and 2018, teacher educators experimented with a variety of pedagogical strategies, most of which situated learning to teach ELLs in diverse classrooms, schools, and communities--both in the United States and elsewhere. The authors conclude that despite having equity goals and including a variety of pedagogically rich ideas for preparing future mainstream teachers to teach ELLs, the vast majority of the studies leave unquestioned the power dynamics that sustain existing educational and social inequalities, thereby perpetuating the status quo.