No written Constitution in the history of mankind has ever successfully restrained government. So long as men and women interpret the Constitution, they can make it mean whatever they want it to mean. And as this book by Robert Levy makes clear, expediency – not principle – usually wins the day. However, in the case of the American ‘War on Drugs’ the infraction is blatantly obvious, and has been well documented by scholars.
During Alcohol prohibition in the 1920s, the American government followed the proper constitutional procedure and amended the Constitution. This was the 18th amendment. As we all know, prohibition failed (there is academic consensus on this point) and created problems far worse than alcohol addiction. The modern-day War on Drugs in America has also failed, can never succeed, and is moreover being conducted illegally.
In Australia the legal situation is somewhat different. The federal government’s primary role is to carry out its customs power under section 51 of the Constitution, and it therefore controls the importation of drugs. The Feds can also legitimately exercise influence on the states in relation to drugs policy. I can’t see a way to get around this, given the Australian Constitution is written in a way that lends itself to a broad interpretation of the enumerated powers.