Abstract: Does the Food and Drug Administration (FDA) have the authority to regulate tobacco and tobacco products? This essay argues that the FDA does have this authority, because of the legitimate role of regulatory agencies in adapting statutory text to new circumstances and values. Without much fanfare, agencies have become modern America's common law courts, and properly so. This general claim is connected to the more particular one: Under the best reading of the FDA, tobacco may or may not be a drug; but under the best reading of that Act, the FDA has the legal authority to treat tobacco as a drug if it chooses to do so. In the process the essay discusses a number of, interpretive questions: the uses and limits of literalism; the power of an agency to change its mind, when Congress and others have been explicitly informed of the previous interpretation; the relevance of recent tobacco legislation; the role of paternalism in regulatory law; the nature of statutory default rules, operating as "information-eliciting" rules or as "intention-eliciting rules"; and the use of "dynamic" statutory interpretation by administrative agencies rather than courts.