By LUKE C. WATERS
This article considers whether federal law preempts state marijuana legalization laws.
1996, California effected a sea change in American
jurisprudence when its voters approved the Compassionate Use
Act,1 the first state-backed, fully
implemented, comprehensive medical marijuana
program2 in the United States. Since then, 31
other states as well as Washington, D.C., Guam, and Puerto
Rico have followed suit, adopting comprehensive medical
marijuana programs of their own.3 In 2012, Colorado and
Washington upped the ante by legalizing recreational
marijuana for use by all adults, with seven states since
following their lead.4 Yet, even as the tide of marijuana
legalization continues almost unabated, numerous political
actors, including President Obama—a former
constitutional law professor—and his
administration,5 eight former Drug Enforcement Agency
(DEA) administrators,6 and states such as Nebraska,
Oklahoma,7 and Arizona,
The answer appears simple enough. Marijuana is, without exception, illegal according to the federal Controlled Substances Act (CSA), under which it is categorized as a Schedule I narcotic.9 The states, for their part, have legalized marijuana to different extents, by either exempting individuals who possess, cultivate, distribute, and use it from state criminal and civil sanctions;10 or by providing those individuals with an affirmative defense to any charges.11 Further, states profit from marijuana via taxing licenses, registration cards, and sales.12 With such flagrant state actions flying in the face of federal law, it seems apparent that a conflict exists and this is the end of the analysis, because federal law must always preempt conflicting state law.13 However, federal supremacy law is not so simple.
answer the question, this article examines federal
preemption, including what constitutes a positive conflict;
how the anti commandeering doctrine fits in, including
application of Murphy v. National Collegiate Athletic
Federal preemption is based on U.S. Const, art. XI, commonly known as the Supremacy Clause, which states "the Laws of the United States... shall be the supreme Law of the Land; and the judges in every State shall be bound thereby, any Thing in the Constitution or Laws of any state to the Contrary notwithstanding."16 To say that Congress's preemptive power is vast would be an understatement, as it is sometimes commonly understood to be nearly absolute. Yet the power of preemption is constrained in meaningful ways, most notably by the fact that, unlike the Commerce Clause, it is not a substantive power.18
Preemption issues arise when both Congress and a state pass laws that regulate the same action. Preemption takes one of three forms: express, field, or conflict. Express preemption is the easiest to identify, as it is defined by federal statute as the "unambiguously expressed intent of Congress" to supersede any related state laws on a given subject.19 If legislative intent does not exist or is unclear, courts may infer preemption, either by finding that the federal government has asserted "field" or "conflict" preemption.
Field preemption occurs when a federal statute is "so pervasive... that Congress left no room for the States to supplement it."20 Conflict preemption requires a less pervasive showing than field preemption, but still requires proof that '"compliance with both federal law and state regulations is a physical impossibility'... or  state law 'stands as an obstacle to the accomplishment and execution of the full purposes and objectives of Congress.'"21 Thus, conflict preemption requires a showing of either a direct or an obstacle conflict. While these definitions seem clear, they are subject to a number of inferences and exceptions. State marijuana legalization, federal marijuana prohibition, and the escalating conflict between the two must be analyzed against this background.
Positive Conflict: A Two-Prong Analysis
Congress created the CSA with a preemption provision, outlining its intent pertaining to the relationship between federal and state laws on the subject of narcotics enforcement. Congress not only excluded express preemption, but also made clear that it had no intent to occupy the field; thus neither express nor field preemption is an issue when determining what standard to apply in evaluating whether the CSA supersedes conflicting state laws.
The CSA states:
No provision of this subchapter shall be construed as indicating an intent on the part of the Congress to occupy the field in which that provision operates, including criminal penalties, to the exclusion of any State law on the same subject matter which would otherwise be within the authority of the State, unless there is a positive conflict between that provision of this subchapter and that State law so that the two cannot consistently stand together.22
In hindsight, Congress's foreclosure of field preemption may seem odd, as Congress could have drafted the CSA to expressly preempt state law or to occupy the field, which would have allowed the federal government to undo state legalization schemes. But Congress's decision was likely a pragmatic one, based on the federal government's finite law enforcement resources. Without the assistance of state law enforcement, the CSA would be largely ineffective. In fact, in any given year, state law enforcement officers are responsible for 99% of all marijuana arrests throughout the United States, including those prosecuted by the federal government.23 It is also unlikely that Congress envisioned a future with states legalizing marijuana en masse.
Notwithstanding the fact that neither express nor field preemption are applicable to the CSA, preemption can yet be asserted when "a positive conflict" exists between federal and state law "so that the two cannot consistently stand together."24 Though seemingly self-explanatory, the positive conflict described in the CSA is the subject of extensive Supreme Court precedent and occurs where there is either a direct conflict or an obstacle conflict.
Is There a Direct Conflict?
As stated in Barnett Bank, N.A. v. Nelson, a direct conflict occurs when "[c]ompliance with both statutes... may be a 'physical impossibility.'"25 The U.S. Supreme Court has consistently construed the concept of "impossibility" between federal and state laws narrowly, so much so that impossibility will not apply, for example, where a federal statute authorizes the sale of insurance and a state statute forbids the sale of the same insurance.26 Recently, in Wyeth v. Levine, the Court reminded litigants arguing in favor of impossibility of their high burden in proving this "demanding defense." It ruled that impossibility did not apply where a state law required a drug manufacturer to change its warning labels after they had been approved by the Food and Drug Administration, because there was no evidence to suggest that the agency would have revoked the amended warning label.27Under the holdings of Barnett Bank and Wyeth, it appears that any action short of explicitly conflicting commands to act one way and also act the exact opposite way would be enough to meet the impossibility prong. It thus appears that the federal government would have a difficult time meeting its burden in arguing for the existence of a direct conflict between the CSA and state marijuana laws.
Further, millions of Americans presumably comply with state marijuana laws every day because no state marijuana law commands an individual to use, cultivate, or distribute marijuana. Rather, these state laws permit individuals to undertake action where the federal government has forbidden it; thus state marijuana laws cannot create impossibility per Supreme Court precedent. The fact that individuals in legalized state marijuana programs are simultaneously complying with both state and federal law frustrates the direct conflict prong.
Is There an Obstacle Conflict?
An obstacle conflict occurs when a state law "stands as an obstacle to the accomplishment and execution of the full purposes and objectives of Congress." A minor inconvenience to federal power is not enough to support a claim that an obstacle conflict exists. In fact, obstacle conflict is...