The dissertations project asks whether and how borders promote authoritarian dynamics within liberal-democratic orders. This line of questioning is made possible by a changed understanding of borders, which no longer exclusively identifies them with the outer demarcation-lines of nation-states. If instead borders are understood as spatially extensive and complex political institutions, it becomes possible to ask how they change societies from within. To this end, the project adopts an interdisciplinary approach that connects political theorizing with existing empirical research that enable a “thick description” (C. Geertz) of the manifold determinations and relations of borders. Practices of bordering, it is argued, (i) produce and exacerbate social antagonisms, (ii) expand the capacities of states to capture people and control their daily interactions, and (iii) enable the circulation of state-sanctioned and extra-legal forms of violence. Along these three axes, the project traces the authoritarian dynamics of borders and their implications for democratic theory. In doing so, it can draw on recent work in political philosophy that has analyzed how basic democratic rights are endangered by increasingly restrictive border and migration regimes. Contrary to these works, however, borders are not understood as alien and external to an enlightened liberal political tradition. Instead, the project argues that borders need to be understood as an integral part of liberal political orders. Complicating previous analyses, the dissertation offers a novel perspective on the relationship between borders, liberalism and democracy: It is the first newer study in political philosophy to analyze how authoritarian dynamics – mediated through different forms of bordering – are already inscribed into the inner organizing principles of liberal-democratic orders themselves. The project thus hopes to show that democratic relations must always be fought for against borders and the violence they bring into the world.