Keywords: John Rawls; Political Liberalism; Legitimacy; Consensus; Public Justification.
In this paper I analyze the theory of legitimacy at the core of John Rawls' political liberalism. Rawls argues that a political system is well grounded when it is stable. This notion of stability embodies both pragmatic and moral elements, each of which constitutes a key desideratum of Rawlsian liberal legitimacy. But those desiderata are in tension with each other. My main claim is that Rawls' strategy to overcome that tension through his theory of public justification is ultimately unsuccessful, because the account of consensus it envisages is unstably placed between the extremes of moralized redundancy and pragmatic free-for-all. In other words, what counts as consensus is either regulated too tightly, or not enough.