Here’s a general debate I’ve been thinking about for a while. Suppose you’re on the constitutional convention for the good citizens of Newlandia, who want to create a new federal system to govern their country: a central government, plus regional states/provinces/Länder. The constitution of Newlandia is to ensure that both the central government and the regional governments have guaranteed areas of legislative authority, which the other level of government cannot usurp.
So that leads to the question: how best to set out the division of powers between the central and the regional governments, to ensure that neither government will be able to trench on the powers of the other?
Do you follow the American model, where there is just one list of powers, for the federal government, with everything else being left to the states? (Constitution of the United States, Article I, §8)
Or do you follow the Canadian model, where there is a list of exclusive federal powers and a list of exclusive provincial powers? (Ignoring for the purposes of this discussion the limited third list of concurrent powers.) (Constitution Act, 1867)
It seems to me that the Canadian model provides greater certainty about the distribution of powers.
I understand that the US model was adopted with the idea that that approach would emphasise that the federal government was to be a government of strictly enumerated powers, with everything else left to the states. However, as a matter of litigation strategy, it seems to me that it is much easier to argue for gradual increase in federal powers over time, because there is always a positive text to point to as the source of a particular federal power, with nothing to counter-balance it on the state side.
By contrast, in the Canadian system, those opposing a particular federal power always can point to a positive text that may support the matter falling under provincial jurisdiction. The courts have to interpret the two lists of powers in a consistent fashion, which has tended to keep the federal government more closely within the boundaries of the original list of federal powers.