Constitutional law
Get on top of constitutional problems.
Constitutional law problems follow a set order: whether there is a head of power, whether the law is valid, and whether any limits apply. Working to that order keeps the analysis controlled. The same approach applies across the topics.
Study it in pieces
The subject, one topic at a time
Constitutional law is a subject of powers and limits, so it is broken into five parts. Open any topic to study it on its own page, with the idea, where it comes from, how it is examined and the trap to avoid. Every topic here is examined as a hypothetical, a problem you solve on the facts. Universities structure these topics differently, so check your subject's reading guide to confirm what's on your syllabus.
New · Practice bank: work 100 exam-style constitutional law problems and 18 full exam scenarios, including 3 mid-semester papers, with Pass and H1 model answers and examiner's comments. →1Commonwealth power
The heads of power and how a law is characterised under them.
2The federal balance
Inconsistency, the immunities and the money power.
3The institutions
Executive power and the two judicial power doctrines.
4Trade and taxation limits
The economic guarantees that police State schemes.
5The freedoms
The implied freedom and the franchise.
The challenge
Where students get stuck
Characterisation is the most common difficulty. It requires identifying the head of power, often in section 51, applying the sufficient connection test, and dealing with dual characterisation and purposive powers. The limits each involve their own test, including section 109 inconsistency, the implied freedom of political communication and its structured test, and the Chapter III limits on courts. Marks go to answers that work through each test in order and with authority, rather than by general impression.
How the guides handle it
The guides start at characterisation and build outward: name the power, state the test with its authority, apply it to what the law does, then take each limit as its own issue. The implied freedom and section 109 run in fixed steps, and the drills work those steps in order.
The method in action
A reliable answer under exam pressure comes from a fixed routine rather than from inspiration. The same four steps run every argument. Below is the routine, then a worked problem that puts it to work. The method is the same for any problem.
The four steps, every time
Worked example
The implied freedom is a limit on power. Each provision is tested in stages.
Do the donation cap and the poster ban burden political communication?
A law is tested by whether it burdens political communication (Lange v ABC). Capping donations "above $500" burdens it because donations fund political communication. Banning posters "within 100 metres" of a polling place burdens it directly. Both clear stage one.
Do the provisions pursue a purpose compatible with representative government?
The purpose must be compatible with the constitutionally prescribed system of representative and responsible government (McCloy v NSW). Preventing corruption is a legitimate purpose for the donation cap. Protecting orderly voting is legitimate for the poster ban. Both clear stage two.
Are the provisions proportionate, that is, suitable, necessary and adequate?
Proportionality asks whether a law is suitable, necessary and adequate in its balance (McCloy v NSW). The "$500" cap is a reasonable means of limiting corruption, so it is likely valid. The "100 metres" poster ban is doubtful. This is because a narrower rule could protect orderly voting without banning all posters across that radius.
What is the result?
The donation cap is likely valid. The poster ban probably fails. This is because it burdens political communication more than is necessary to protect orderly voting.
Now the same answer, dissected step by step.
The implied freedom is a limit on power. Each provision is tested in stages.
Sets out the issues and the order they are taken.
Do the donation cap and the poster ban burden political communication?
A law is tested by whether it burdens political communication (Lange v ABC). Capping donations "above $500" burdens it because donations fund political communication. Banning posters "within 100 metres" of a polling place burdens it directly. Both clear stage one.
Applies the burden question to each provision with authority.
Do the provisions pursue a purpose compatible with representative government?
The purpose must be compatible with the constitutionally prescribed system of representative and responsible government (McCloy v NSW). Preventing corruption is a legitimate purpose for the donation cap. Protecting orderly voting is legitimate for the poster ban. Both clear stage two.
Tests purpose against the constitutional system with authority.
Are the provisions proportionate, that is, suitable, necessary and adequate?
Proportionality asks whether a law is suitable, necessary and adequate in its balance (McCloy v NSW). The "$500" cap is a reasonable means of limiting corruption, so it is likely valid. The "100 metres" poster ban is doubtful. This is because a narrower rule could protect orderly voting without banning all posters across that radius.
Weighs suitability, necessity and balance, where the two provisions diverge.
What is the result?
The donation cap is likely valid. The poster ban probably fails. This is because it burdens political communication more than is necessary to protect orderly voting.
Reaches different results and pins the reason to proportionality.
The implied freedom protects political communication. Both laws restrict it because donations and posters are political. The government has good reasons, stopping corruption and keeping polling places orderly. But the laws go too far and breach the freedom, so they are invalid. People have a right to political communication and these laws take it away.
This is a pass-level answer. Click each line to see where the marks are lost.
Spending your time under pressure
A workable time split for a 45 minute problem. Adjust it to suit your exam.
Now try one
Work it yourself using IRAC. Fill in each step, then submit to self-check and reveal the model answer.
Issue. Whether the three-day social media advertising ban infringes the implied freedom.
Rule. The law must burden political communication, pursue a legitimate purpose, and be proportionate (McCloy v NSW).
Application. A ban on "all political advertising on social media" burdens communication. Preventing misinformation is legitimate. However, a total ban on a whole medium for three days is likely not necessary.
Conclusion. The ban probably fails. This is because it is disproportionate, burdening communication more than is necessary.
Common questions
Constitutional Law: common questions
Does this cover power and the limits?
Yes. Characterisation and the heads of power. Section 109. The implied freedom. The Chapter III limits.
Characterisation confuses me. Where do I start?
It is the spine of the subject. The characterisation guide sets out the sufficient connection test, dual characterisation and the purposive powers, and the defence-power drills, labelled Defence and characterisation in the practice bank, put the test to work on facts.
Section 109: which test do I run first?
Start with direct inconsistency: can both laws be obeyed at once, and does the State law take away a right or privilege the Commonwealth law confers (Clyde Engineering v Cowburn; Colvin v Bradley Brothers)? Only then ask whether the Commonwealth law covers the field (Ex parte McLean; Wenn v Attorney-General (Vic)). The consequence is that the State law is inoperative to the extent of the inconsistency, not invalid.
What does the Kable principle actually stop a State doing?
It stops a State Parliament giving a State court a function that is repugnant to or incompatible with its role as a repository of federal judicial power under Chapter III (Kable v DPP (NSW)). The question is institutional integrity, not a State-level separation of powers: does the function undermine the court's independence, impartiality or decisional independence? Most challenges fail (Fardon); Kable, International Finance Trust, Totani and Wainohu are the ones that succeeded. Kirk adds that the supervisory jurisdiction of a State Supreme Court cannot be removed.
Section 92: is it still about protectionism?
For trade and commerce, yes. Since Cole v Whitfield the guarantee catches only laws that discriminate against interstate trade in a protectionist sense, in form or in effect. Betfair v Western Australia adds that a law with a legitimate non-protectionist purpose survives only if it is reasonably necessary for that purpose. The intercourse limb, the movement of people across borders, is tested separately: Palmer v Western Australia accepts that it can be burdened where the restriction is reasonably necessary for a legitimate purpose.
Related subjects: Principles of Public Law, Administrative Law, Criminal Law & Procedure. See all subjects.
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