Most of the existing literature or judicial interpretation of federal constitutions focuses either on individual federations or on comparative studies of specific judicial techniques and/or specific fields. This paper argues that the general interpretative philosophy underlying the judicial approach has a huge impact on the balance of power in a federation; an originalist interpretation tends to favour the constituent units, while progressive or "living" constitutionalism tends to have a centripetal effect. However, even the adoption of an originalist approach is not sufficient to fully counter the general centralising trend noticeable in the constitutional jurisprudence of all the federations studied. Further, the analysis suggests that constitutional courts often adopt a different approach to interpretation in federalism-related issues than they do in other areas of constitutional law, such as fundamental rights.