The “new originalism” is all about the text of the Constitution. Originalists insist that the whole point of originalism is to respect and follow the original meaning of the text, and that originalism derives its legitimacy from its unwavering focus on the text alone as the sole basis of higher law. And yet, many leading Supreme Court decisions in matters of great importance to conservatives—in opinions authored and joined by originalist judges, and often praised by originalist scholars—are seemingly not grounded in the constitutional text at all. They rest instead on abstract structural argument: on freestanding principles of federalism and separation of powers in lieu of the original meaning of any particular provision of the Constitution...