This article uses a Latina/o critical theory framework (LatCrit), as a branch of critical race theory (CRT) in education, to understand how discourses of racist nativism--the institutionalized ways people perceive, understand and make sense of contemporary US immigration, that justifies "native" ("white") dominance, and reinforces hegemonic power--emerge in California public K-12 education for Chicana students. I use data from 40 "testimonio" interviews with 20 undocumented and US-born Chicana students, to show how racist nativist discourses have been institutionalized in California public education by English hegemony, that maintains social, political, and economic dominance over Latina/o students and communities, regardless of actual nativity. Teacher practices of English dominance is a manifestation of this hegemony that can be articulated by the concept of racist nativist microaggression--systemic, everyday forms of racist nativism that are subtle, layered, and cumulative verbal and non-verbal assaults directed toward People of Color. (Contains 12 notes and 3 figures.)