It's completely trivial to cross between states inside the US, but if the next state over legalizes marijuana, and you take a road trip to bring back some weed

It's completely trivial to cross between states inside the US, but if the next state over legalizes marijuana, and you take a road trip to bring back some weed and edibles, by crossing state lines your road trip may become a Federal drug trafficking offense, with severe penalties if caught. Even the easiest border crossing can carry significant risks depending on the context.