Because the fundamental problem of federal design is to supply a stabilizing institutional context for bargaining over inherently redistributive policy, and because these institutions, many of which are constitutional, are themselves subject to negotiation and reinterpretation, the idea of a constitution as a living document reflects the conventional wisdom that such things as the division of prerogatives and jurisdictions between federal subjects and the federal center should not be impervious to adjustment and redefinition as society evolves and circumstances change. If these adjustments are to remain incremental and evolutionary, however, then bargaining and renegotiation must be set in some larger and stable institutional context – a layer of institutional structure that is somehow further removed from the pressures of bargaining but which nevertheless directly impacts and regulates it. And if, for convenience, we label such institutions “constitutions” in a broad sense, then an essential part of federal design, as we outline matters in the previous chapter, is to create a constitutional supergame that encompasses federal bargaining and restrains it so that Level 1 provisions are more than mere words on paper.