Libertarians do not fit into the left-right spectrum very comfortably; by their own account, they transcend it. This brief paper, written for a Chapman Law Review symposium on libertarian legal theory, argues that libertarians should likewise transcend the dichotomy currently dividing constitutional theory. The Left tends to regard the Constitution as adaptable to current needs and defined by judicial authority; the Right tends to search the historical record for the Constitution’s original meaning. Each of those conventional approaches has its own virtues and vices. Combining the best of both — the responsiveness of living constitutionalism and the textual fidelity of originalism — generates a distinctly libertarian theory designed to maximize the consent of the governed and, thus, the justifiability of constitutional authority.