Whether "medical marijuana" (Cannabis sativa used to treat a wide variety of pathologic states) should be accorded the status of a legitimate pharmaceutical agent has long been a contentious issue. Is it a truly effective drug that is arbitrarily stigmatized by many and criminalized by the federal government? Or is it without any medical utility, its advocates hiding behind a screen of misplaced (or deliberately misleading) compassion for the ill? Should Congress repeal its declaration that smoked marijuana is without "current medical benefit"? Should cannabis be approved for medical use by a vote of the people as already has been done in 13 states? Or should medical marijuana be scientifically evaluated for safety and efficacy as any other new investigational drug? How do the competing--and sometimes antagonistic--roles of science, politics and prejudice affect society's attempts to answer this question? This article examines the legal, political, policy, and ethical problems raised by the recognition of medical marijuana by over one-fourth of our states although its use remains illegal under federal law. Although draconian punishment can be imposed for the "recreational" use of marijuana, I will not address the contentious question of whether to legalize or decriminalize the use of marijuana solely for its psychotropic effects, a fascinating and important area of law and policy that is outside the scope of this paper. Instead, the specific focus of this article will be on the conflict between the development of policies based on evidence obtained through the use of scientific methods and those grounded on ideological and political considerations that have repeatedly entered the longstanding debate regarding the legal status of medical marijuana. I will address a basic question: Should the approval of medical marijuana be governed by the same statute that applies to all other drugs or pharmaceutical agents, the Food, Drug, and Cosmetic Act (FD&C Act), after the appropriate regulatory agency, the Food and Drug Administration (FDA), has evaluated its safety and efficacy? If not, should medical marijuana be exempted from scientific review and, instead, be evaluated by the Congress, state legislatures, or popular vote? I will argue that advocacy is a poor substitute for dispassionate analysis, and that popular votes should not be allowed to trump scientific evidence in deciding whether or not marijuana is an appropriate pharmaceutical agent to use in modern medical practice.