Earlier quoted context omitted.
While I disagree that legalization will be "just a blip", it's interesting to note that the original law that prohibited marijuana in the US was actually a cleverly worded tax law: https://en.wikipedia.org/wiki/Marihuana_Tax_Act_of_1937 Basically, marijuana was legal, but you were required to purchase a tax stamp (that was never issued) in order to prove that you had paid taxes on it. There were many reasons for this…
That is because Congress has enumerated powers, and the Commerce Clause was then accepted in the intended meaning of only controlling commerce with other countries, between the states, and with Indian tribes. Sales inside of a state are obviously out of the purview of that clause. Today, of course, the Commerce Clause is interpreted insanely broadly to cover everything from civil rights to environmental protection. W…
While the framers probably didn't fully understand the ramifications, I think the broad language of the Commerce Clause lends itself to a fair reading that Congress can act on matters in which individual states acting alone would face collective action or race to the bottom problems. So something like environmental regulations fits quite naturally into this framework. Pollution doesn't respect state bounderies and states face a race to the bottom problem in attempting to regulate it. Therefore Congress is empowered to act.