This book explores the Office of Legal Counsel (OLC) in the U.S. Department of Justice. Its scope is a comprehensive study of the Office—history, functions, and impact on governmental decisions (mainly presidential and legal positions of the executive branch but also the Office’s actions influence either Congressional or federal judicial decisions). The book focuses on the evolution of the OLC over the last few decades, how the office straddles the line between politics and law, as well as how it interacts with the rest of the Department of Justice. The main argument is that the OLC provides an essential role for both the president and the rest of the national government but does not receive nearly the attention or scrutiny it deserves.