In an apparent victory for federalism, the Obama Administration has set out a policy of deference to state marijuana regulations, even when state laws conflict with federal prohibition. Critics of this policy have alleged that the executive is unconstitutionally leaving portions of federal law unenforced, effectively legalizing a drug that is still classified as a Schedule 1 narcotic. But in reality, current executive branch guidelines for the exercise of prosecutorial discretion are limited, vague, and largely unenforceable. Instead, the real risk is not that current federal nonenforcement policy will effectively legalize marijuana, but that the policy will fail to induce the reliance necessary for states to serve as effective laboratories of experimentation. This concern can be addressed, to an extent, by requiring that U.S. Attorneys use their enforcement authority in a more formal, transparent, and reliable fashion. However, constitutional limits on executive power mean that deregulation is likely to remain imperfect until a legislative solution is enacted.