Division of powers

In a federation, the division of power between federal and regional governments is usually outlined in the constitution. It is in this way that the right to self-government of the component states is usually constitutionally entrenched. Component states often also possess their own constitutions which they may amend as they see fit, although in the event of conflict the federal constitution usually takes precedence.

In almost all federations the central government enjoys the powers of foreign policy and national defense. Were this not the case a federation would not be a single sovereign state, per the UN definition. The states of Germany retain the right to act on their own behalf at an international level. Beyond this the precise division of power varies from one nation to another. The constitutions of Germany and the United States provide that all powers not specifically granted to the federal government are retained by the states. The Constitution of Canada, on the other hand, states that powers not explicitly granted to the provincial governments are retained by the federal government. Much like the US system, the Australian Constitution allocates to the Federal government (the Commonwealth of Australia) the power to make laws about certain specified matters which were considered too difficult for the States to manage, so that the States retain all other areas of responsibility.

Where every component state of a federation possesses the same powers, we are said to find 'symmetric federalism'. Asymmetric federalism exists where states are granted different powers, or some possess greater autonomy than others do. This is often done in recognition of the existence of a distinct culture in a particular region or regions. In Spain, " historical communities" such as Navarre, Galicia, Catalonia, and the Basque Country have more powers than other autonomous communities, partly to deal with their distinctness and to appease nationalist leanings, partly out of respect of privileges granted earlier in history.

Usually, a federation is formed at two levels: the central government and the regions (states, provinces, territories), third level political entities are rarely officially mentioned. Brazil is an exception, because the 1988 Constitution included the municipalities as autonomous political entities making the federation tripartite, with the Union, the States, and the municipalities. Each state is divided into municipalities (municí pios) with their own legislative council (câ mara de vereadores) and a mayor (prefeito), which are partly autonomous from both Federal and State Government. Each municipality has a “little constitution”, or “organic law” (lei orgâ nica).