"A constitution," said Napoleon, "should be short and obscure." The drafters of the United States Constitution agreed. Both the original document of 1787 and its key amendments are notoriously so. What is the "executive power" which is vested in the president? Do his powers as "Commander in Chief of the Army and Navy" extend to civilian functions? What constitutes the "commerce" among the states that Congress may regulate? What constitutes an "establishment" of religion? What are the elements of the "liberty" and "property" which may not be deprived without "due process?" Who are the "persons" who may not be deprived of them, and what "process" is "due" in depriving them? What protection of the law is "equal," and what persons and relations are alike for purposes of equality? Untold amounts of time, ink, and on one occasion blood, have been devoted to these conundrums. They are today the subject of vehement political controversy, not least on the issue of whether any element of human sexuality is to be counted as part of the liberty and equality protected by the Fourteenth Amendment against interference by state governments.

Napoleon's point was that vagueness confers political power on the person or institution that has the final authority to interpret and apply constitutional language. In our system, that is the United States Supreme Court. For most of its history, the court was primarily the defender of the propertied minority against majorities at both the state and federal level. Since approximately 1937, however, it has been both the protector of national authority over the economy and the guardian of previously powerless racial, gender and sexual groups against arbitrary repression. Those roles have been far from universally accepted. From at least the 1980s, there has been a sustained intellectual and political campaign to undo the post-New Deal constitutional order and return to a regime where there is a presumption against government regulation and where local majorities are left free from constitutional restraint on their own racial, religious and cultural preferences. That campaign has enjoyed the sustained support of the Republican party, and it has finally borne fruit in the court's membership after President Trump's three appointments.