Abstract: Alongside the regulative and integrative functions we theorize for constitutions, a function of legitimation perhaps deserves a focus of its own. By legitimation, I mean the social and communicative processes by which a country’s people sustain among themselves a sense of assurance of the deservingness of its political regime of general and regular support. On the level of political philosophy, the idea of the constitution as a platform for legitimation finds expression in John Rawls’s proposal – named by him as “the liberal principle of legitimacy” – that enactments by political majorities can be justified to dissenters in any given case (regardless of which side of the case you might think true justice and policy would favor) by a showing that the winners have acted within the terms of a good-enough (in the paper’s terms, a “legitimation-worthy”) constitution. The Rawlsian proposal figures as one for what the paper calls “legitimation by constitution” or “LBC.” The paper posits, as a hypothesis, the activity of this idea in a population’s political consciousness, with a view to tracing resultant effects on constitutional-legal practice and debate. As a prime case in point, the paper points to an apparent correlation, within the world of broadly-speaking liberal constitutional thought, of a recent spread of receptivity to the idea of “weak-form” judicial constitutional review with a spread, within that same world, of conviction that a legitimation-worthy constitution would have to include guarantees respecting the so-called socioeconomic rights of citizens vis-a-vis their states. The paper suggest that LBC (the idea) provides a hinge between these two developments.