This book traces the recent socio-historical trajectory of educational language policy in Arizona, the state with the most restrictive English-only implementation in the United States. Chapters, each representing a case study of policy-making in the state, include: (1) SEI in Arizona: Bastion for States' Rights (Karen E. Lillie and Sarah Catherine K. Moore); (2) "Flores v. Arizona" (Tim Hogan); (3) Proposition 203 and Arizona's Early School Reform Efforts: The Nullification of Accommodations (Wayne E. Wright); (4) Ensuring Oversight: Statewide SEI Teacher Professional Development (Sarah Catherine K. Moore); (5) (Mis)aligned Curricula: The Case of New Course Content (Amy Markos and Beatriz Arias); (6) Exploring Principals' Concerns Regarding the Implementation of Arizona's Mandated SEI Model (Giovanna Grijalva and Margarita Jimenez-Silva); (7) The Four-Hour Block: SEI in Classrooms (Karen E. Lillie and Amy Markos); and (8) Conclusion: The Consequences of Nullification (Terrence G. Wiley).