This chapter discusses whether Singapore is best normatively thought of as having a 'legal constitution' or a 'political constitution'. It distinguishes between claims about interpretive authority and claims about interpretive legitimacy. The chapter also distinguishes between two broad kinds of foundations for constitutional legitimacy, what we might call static foundations and dynamic foundations. It notes that legal understandings of constitutionalism tend to be associated with more mature and more stable constitutional systems. The chapter addresses the two cases Michael W Dowdle cites as being instances that show Singapore to be operating under political constitutionalism. Dowdle argues strongly that Singapore is best normatively thought of as having a political constitution rather than a legal one. Constitutional systems can also evince different foundations of legitimacy at different times in their history and can oscillate between static and dynamic foundations in response to larger evolutions in their socio-economic environment. A legal constitutionalism advises that constitutional disputes should be resolved by the courts.