Robert P. George in the New York Times Book Review:
In “America’s Unwritten Constitution,” Akhil Reed Amar, a commendably unorthodox and, in some ways, iconoclastic constitutional scholar at Yale Law School, bucks dominant opinions on both sides of the political spectrum. He contends that the written Constitution points to an unwritten one, and he argues that we can interpret with both intellectual honesty and analytical rigor. Aware that the idea of an unwritten constitution has been abused by judges and scholars on both the left and right, Amar insists that the idea itself is sound — indeed indispensable to the cause of constitutional fidelity — and needs rescuing from its abusers.
Liberal jurists and legal scholars are accused, often justly, of failing to take the text of the Constitution seriously, or to seek the meaning of its written provisions by understanding them in their historical context. They treat concepts like “due process of law” and “the equal protection of the laws” as, in the words of the liberal justice William J. Brennan Jr., “majestic generalities” that can be assigned whatever meanings would best serve the cause of justice as they happen to perceive it.
Historically, it has not been only liberals who have stood under indictment for this offense. At the height of the Industrial Revolution, a conservative-dominated Supreme Court struck down a state law restricting work hours, citing an implicit right to freedom of contract between employers and workers. Critics of laissez-faire ideas about economic justice accused the court’s members of manufacturing this right to serve their ideological purposes.