My understanding is the president cannot fully legalize cannabis on their own. Best thing they can do is stop enforcement at the federal level, but the president can't stop states from continuing to enforce it at the state level.
The president can do that, but states are still allowed to have their own drug laws. States can't make something illegal if there is a federal law saying it's legal. States can make something illegal if there is no federal law regarding it. It's why states can make abortion laws since there's no federal abortion law.
Descheduling cannabis is essentially the same thing as having no federal law and letting the states decide. It's not the same as legalization.
Right! So what would descheduling cannabis do? Nothing! The federal government is already choosing to not enforce their own law. Changing the federal scheduling of cannabis doesn't actually change anything if the federal government isn't enforcing it to begin with. I mean, it's not like it's a bad thing, it's just not the same as federal legalization.