Explain how the Australian Constitution establishes federalism and divides law-making power between the Commonwealth and the states.

What this dot point is asking

This dot point asks you to explain what the Constitution is, how it created a federal system, and how it splits law-making power.

What the Constitution is

The Commonwealth of Australia Constitution Act came into force on 1 January 1901, joining the former British colonies into one federation while allowing each to keep its own parliament. The Constitution is the supreme law: it sets out the structure of the Commonwealth Parliament, the executive and the judiciary, and it defines and limits the Commonwealth's powers. Any Commonwealth law that goes beyond these powers is invalid, and the High Court is the final interpreter of what the Constitution means.

The division of powers

The Constitution divides law-making power into three categories:

• Exclusive powers can only be exercised by the Commonwealth. Examples include defence (limited to the Commonwealth by section 114), coining money (section 115) and customs and excise (section 90).
• Concurrent powers are shared between the Commonwealth and the states, who can both legislate on them. Most of the powers listed in section 51, such as trade and commerce, marriage, and taxation, are concurrent.
• Residual powers are those not listed in the Constitution and therefore left to the states. These include most criminal law, health, education, transport and land. This is why Tasmania makes most of the everyday law affecting Tasmanians.

Section 109 and inconsistency

Because the Commonwealth and the states can both legislate on concurrent matters, their laws can conflict. Section 109 resolves this: where a valid Commonwealth law and a state law are inconsistent, the Commonwealth law prevails to the extent of the inconsistency, and the state law is invalid only to that extent. This gives the Commonwealth the upper hand in shared areas and is a key reason Commonwealth power has expanded over time. Importantly, section 109 does not destroy the state law permanently: it makes the state law inoperative only while the inconsistency lasts, so if the Commonwealth law is later repealed the state law can revive. The High Court has read inconsistency broadly, including where the Commonwealth law is intended to be a complete statement of the law on a topic (covering the field), which further strengthens national power in shared areas.

How the balance has shifted

Although the states began with broad powers, the Commonwealth has become more dominant. This has happened through High Court interpretation that reads section 51 powers broadly, through the Commonwealth's control of major taxation (giving it financial power over the states through grants under section 96), and through use of the external affairs power to legislate on matters covered by international treaties. The result is a more centralised federation than the framers may have envisaged, even though the formal division of powers in the text has barely changed.

For exam answers, explain that the Constitution created a federation, define the three categories of power with examples, and use section 109 to show how conflicts are resolved in favour of the Commonwealth.