How effective are different political institutions, policy-making processes and policies when it comes to mediating, mitigating and managing vertical and horizontal political tensions caused by disruptive societal challenges and political polarization? The present crisis for liberal democracy places this question high on the research agenda. A concept of political robustness is helpful for identifying the properties of political systems with a strong capacity for coping with political instability and conflict. This article defines political robustness, draws the contours of a conceptual framework for analysis of the political robustness of political systems and applies it illustratively to the political robustness of liberal democracies. We propose that the robustness of a political system depends on how much those who voice political demands—which differs greatly over time and between regimes—are involved in aggregating and integrating political demands into binding decisions.