Whatever we think of judge-made law attempting to read Congress’s unexpressed mind, allowing states to restrict commerce in something the federal government expressly refrains from legalizing (because it doesn’t know how ) helps the goal of allowing states to run experiments, even bad ones, with all the freedom we can muster , as we try to figure out how to legalize federally. Let the Labs of Democracy percolate.
And wouldn’t Congress opposed to marijuana applaud any restrictions states might put on?