The revitalization of republican political thought over the last thirty years has sought to make republicanism an instrument of reflection for the predicaments of contemporary democracies. Beset by authoritarian populism and the rise of non-democratic states such as China, modern democracy, by many accounts, is in crisis. Although republicanism has traditionally been concerned with the mortality of popular governments, neo-republican scholars have instead enlisted republicanism primarily to present republican liberty as a normative ideal to be maximized. Republicanism, these scholars assert, is defined by the ancient Roman stress on freedom from arbitrary domination. Recent criticisms of this account have underscored the historical tension between republican freedom and the notion of human equality that necessitates its universalization. This article pursues a different line of revision by suggesting a twofold legacy of republican political theory. From the chronicles of Rome’s moral and political degeneration Anglophone republicans emphasized the fragility of freedom. Using the transmission of republican theory to the American founding as a privileged vantage point, this article argues that republicanism demands non-domination, but also grounds liberty to a conception of republican mortality. From the republican tradition, the Founding generation inherited a strong attachment to its insistence on freedom from arbitrary domination. Yet equally from the “Atlantic republican tradition” they received a perception that republics were short-lived. The analysis suggests that through a traditional republican vigilance against corruption, contemporary republican theory and democracy can find strength in the republican narrative of Decline and Fall first opened by Sallust.