Contemporary political theory is characterised by a realistic critique of liberalism. Realist theorising is seen as avoiding foundational disagreements about justice mutating into second-order disputes concerning the justifiability of legitimate political institutions. In this sense, the realist critique challenges a key aspect of Rawls’ liberal project – that is, its justificatory constituency. McCabe’s Modus Vivendi Liberalism presents an interesting case of such a critique. Given the condition of deep pluralism that characterizes contemporary democracies, the liberal Justificatory Requirement (JR) should be (...) recast so to include those, illiberal or sceptical, who are excluded by Rawls’ justificatory constituency. This paper confronts McCabe’s modus vivendi justificatory project with Rawls view. It suggests that both views seem to endorse a practice-dependent account of political justice in which “politics is prior to morality”; yet the ways in which reasons are endorsed to justify the shared conception of political authority are significantly different in these two schemes. The paper shows that the most problematic aspect of McCabe contingent model is that it disconnects the idea of legitimacy from a conception of liberal political morality. On this account, political legitimacy that reflects the uncoercive character of extant institutions seems to be sufficient to meet the MVL JR. Yet, from a normative point of view, this might be not enough to ensure morally acceptable outcomes. In conclusion, the paper considers McCabe’s model as a version of ‘practice-independent’ moral theorizing committed to a transcendent view of ‘threshold morality’. This move, however, comes at the cost of sacrificing the theory’s premises of anti-perfectionism and realism. (shrink)