This chapter draws on methods from critical discourse analysis (CDA) to explore the origins and impact of Minnesota’s 2004 Adult Basic Education (ABE) Policy on Teaching Languages Other Than English, characterized by the authors as a state-level adult English literacy development (ELD) policy potentially restricting the use of multilingual adults’ first languages (L1). The authors examine the ways in which a policy’s claims of authorization led to the apparent (de)legitimation of that policy. Specifically, they elucidate contradictions in Minnesota’s ABE policy that complicate the tasks of ABE instructors—namely, that by following the policy’s restrictions on L1 use instructors are forced to engage in instructional practices that are misaligned with recommendations made by the policy’s authorizers. Their analysis traces named authorizers within this policy through state and federal levels to determine its internal legitimacy and its breakdowns. Where breakdown points are found, the authors reveal ideologies and sociohistorical factors both constructing and sustaining the policy. Using legitimation as part of a critical discourse analytis approach, concurrent with a broad historical-political lens, the findings reveal specific articulations of nativist and monoglossic ideologies in the political and economic ecology of the policy’s formation and solidification. Using the results of this work, the authors advance the notion of ‘vacant-core policy’ as language policy de-authorized and de-legitimized by a trail of named authorizers. From this, the authors argue that conceptualizing policies in line with the ‘vacant core’ notion provides opportunities to disrupt and expand the established covert versus overt language policy dichotomy. This chapter offers an analytical lens adaptable to other LPP contexts, thus opening possible avenues for studying (a) policy (in)consistencies and (il)legitimacies, and (b) the multifarious ways policies are mediated and transgressed by practitioners and learners as agentive language users.