Very briefly. Until recent history the 10th amendment was understood to constrain the government from going outside enumerated powers, like intrastate commerce. This is why they needed an amendment instead of law to federally outright ban alcohol. Thus weed had an essentially unpayable 'tax' that got overturned by Timothy Leary

Then it was legal for like a year until feds realized they didn't need to follow the Constitution and they just outright made it illegal, no matter if it's actually interstate.