This Article examines the role of political polarization in contributing to acute infrastructural dysfunction. It begins by applying an infrastructural lens to the study of law, identifying the synergies and tensions inherent in that conversation. The second section investigates the components of a functional border legal infrastructure from a range of perspectives, seeking to understand the performative role of the border. The Article next presents three case studies of politically polarized border legal infrastructures, highlighting material, relational, and distributional elements. Drawing from those examples, the Article then unpacks the role of law as border infrastructure, highlighting the contribution that a legal perspective can offer to the infrastructures literature. This section examines the layers of law involved in border infrastructures, including international, regional, and bilateral; the regulatory role of national law in constructing and governing infrastructures; and the jurisdictional functions of law in allocating the political and financial authority that are essential to the effective operation of infrastructures. This analysis highlights the role of discretion and opacity, as well as political polarization, in setting the stage for infrastructural breakdown. The Article ends by reflecting on the recursive relationship between politics and law in border infrastructures, examining how that dynamic creates and manifests failures, dysfunction, and acute breakdown.