The Constitution allows the Congress to regulate interstate commerce (but NOT intrastate commerce), so Congress says, "Fine, in order to regulate interstate commerce, we must regulate intrastate commerce."
.....and the SC says, "OK....fine then."
If the citizens knew in 1789 that the Federal Government could imprison you for growing hemp under the provisions of the Commerce Clause, they would have never, ever allowed its ratification. The farmers of NY were dubious enough of it to begin with; Alexander Hamilton and the rest of the business classes would have never prevailed in the NY ratification convention and the whole thing would have gone down in flames.
To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes;so my reading is that the Federal government has the same power as regards commerce over the States as it has over foreign nations, which is to say not much. Can you imagine us telling the Netherlands to close down their Tea Houses?
ML/NJ