Why are national constitutional courts able to affect the actions of national legislatures? The roles and relationships of both constitutional courts and legislatures are defined in the national constitution. Although there is variance across countries, in general constitutional courts are empowered to ensure that laws conform to the principles and values enshrined in the constitution. National legislatures are, at least to some extent, required to conform legislation to the decisions of the constitutional court. Yet both the constitutional court and legislature could alter or avoid these roles. Constitutional courts can expand or contract their duties by applying the constitution in either a broad or restricted manner. Similarly, national legislatures can expand or contract the influence of the constitutional court by complying with or ignoring past and future constitutional court decisions.

This dissertation builds on the works of Fish and Kroenig (2009), Schimmelfinning (2006), Maveety and Grosskopf (2004), Finnemore (2003), and Stone (1990) to explain the balance of power between national constitutional courts and national legislatures in the protection and extension of fundamental rights and democracy. By creating a measure of constitutional court autonomy and using both qualitative and quantitative methods, this dissertation will seek to demonstrate that national constitutional court and legislative autonomy must be viewed from both the national and supranational perspective and that a reduction in national legislative autonomy may increase national diffusion of democratic norms and the protection of human rights.