Australian politics is organised in profoundly territorial terms. The fundamental reason for this is the essential role played by the constituent states within the Australian federal system. Historically, the states predated the federation and were the presupposition of its very existence. At the time of federation, they offered the essential and unavoidable political infrastructure upon which the entire federal edifice depended, and continues to depend. The constitution entrenched their role and, despite important tendencies towards centralisation, the Australian states cannot be easily abolished or sidelined. Australia’s party system reflects and reinforces the existence of a politics which is both national and regional in its dimensions. Moreover, and underlying diversity between Australia’s states, regions, cities and towns, underscores the need for the kind of policy diversity and policy responsiveness that the Australian federal system makes possible.