Jacob Sullum points out that prohibition "was resisted in the wetter provinces of America, where the authorities often declined to enforce it":

[Prop 19's] detractors claimed legalizing marijuana at the state level would run afoul of the Supremacy Clause, which says “this Constitution, and the laws of the United States which shall be made in pursuance thereof…shall be the supreme law of the land.” Yet even under a prohibition system that, unlike the current one, was explicitly authorized by the Constitution, states had no obligation to ban what Congress banned or punish what Congress punished. In fact, state and local resistance to alcohol prohibition led the way to national repeal.

He later writes that this precedent should be treated with caution given "federalism isn’t what it used to be."

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