Explain how the Constitution is changed through referendum under section 128 and how the balance of power between the Commonwealth and the states has changed over time.

What this dot point is asking

This dot point asks you to explain the formal process for changing the Constitution and the informal ways the federal balance has actually shifted.

Formal change: section 128 referendum

The text of the Constitution cannot be changed by an ordinary Act of Parliament. Section 128 sets out a special process:

• A bill to alter the Constitution must be passed by an absolute majority of both houses of the Commonwealth Parliament (or by one house twice in certain circumstances).
• The proposal is then put to the people at a referendum.
• It succeeds only if it achieves a double majority: a majority of all voters nationally, and a majority of voters in a majority of states (at least four of the six states).

Why most referendums fail

Of the 44 or so referendum proposals put to the people, only eight have succeeded. The double majority is demanding, because a proposal can win the national vote yet fail because it did not carry four states. Other reasons include bipartisan support being rare, voters tending to vote no when they are uncertain, and the difficulty of explaining complex constitutional change. A successful example was the 1967 referendum, which passed with overwhelming support and allowed the Commonwealth to make laws for Aboriginal and Torres Strait Islander peoples and count them in the census. A recent unsuccessful example was the 2023 referendum on an Aboriginal and Torres Strait Islander Voice to Parliament, which failed to gain a national majority or a majority of states.

Informal change: how the balance has shifted

Even though the text rarely changes, the balance of power between the Commonwealth and the states has shifted markedly toward the Commonwealth:

• High Court interpretation: the court has read Commonwealth powers broadly. The Engineers Case (1920) rejected a narrow reading of Commonwealth power, widening federal authority.
• Financial dominance: since the Commonwealth gained sole control of income tax during the Second World War, the states have relied on Commonwealth grants under section 96, which often come with conditions. This is called vertical fiscal imbalance.
• External affairs power: by entering international treaties, the Commonwealth can legislate under section 51(xxix) on matters that would otherwise be state responsibilities, as seen in the Tasmanian Dam Case (1983), where the Commonwealth stopped a dam to honour a world heritage treaty.

Why this matters

These shifts show that a constitution can stay almost the same on paper while the real distribution of power changes significantly. For Tasmania, financial reliance on the Commonwealth and the reach of national laws affect how much genuine autonomy the state holds. As one of the smaller and less populous states, Tasmania benefits from the double majority safeguard, because its voters help decide whether four states approve a change, but it is also the most exposed to vertical fiscal imbalance, since it raises relatively little of its own revenue and depends heavily on Commonwealth grants. This tension between formal protection and practical dependence is a useful Tasmanian angle to bring into an answer.

For exam answers, set out the section 128 process and the double majority, explain why referendums usually fail with a real example, then contrast this with the informal shift of power to the Commonwealth through interpretation, finance and external affairs.