In this article the author investigates how 20 White preservice teachers, who successfully completed a semester-long diversity course for teacher licensure, developed a critical self-awareness regarding the causes and consequences of linguicism in school settings. The conceptual framework draws from Nieto's 2006 five-level model of Multicultural Education Support to illuminate how White preservice teachers' views toward language diversity shifted from Level 1/Monocultural and Deficit or Level 2/Tolerance mindsets, to frameworks that minimally embraced Level 3/Acceptance of linguistic varieties in the classroom. Using a mixed-methods approach, this study drew from data including a demographic survey, focus groups, instructor-generated reflective journals, one-on-one interviews, and student work samples. This article also offers sample course activities that actively engaged preservice teachers in critical conversations and ongoing reflection about the causes and consequences of linguicism in U.S. schools and society, as well as potential solutions with practical implications for P-12 classrooms.