"Scarcely any political question arises in the United States," Alexis de Tocqueville observed in the 1830s, "that is not resolved sooner or later into a judicial question."
The Supreme Court stands at the crossroads of American life, not merely elaborating and indeed discovering hidden rights of citizens, but defining eras, a living signpost to evolving political and social values. From slavery to abortion and the death penalty, from school segregation, to gender discrimination, to the place of religion in society, and, almost above all, to the central question of American politics, states' rights: on all these the court has set the parameters of political action, often for generations at a stretch.
Such issues have deeply divided a court where reformers and conservatives have also battled over the very nature of their task as judges. Judicial activism vies with the "strict constructionists", akin to Biblical literalists, who see the constitution as cast in stone, immutable, and bitterly resent the notion of judge as proxy legislator.
For 40 years years the conservative right has regarded the court as the ultimate prize needed to consolidate the political domination it has wielded for most of that period in both other arms of government. A series of Republican appointments - John Paul Stevens, Sandra Day O'Connor, Anthony M. Kennedy, David H. Souter - have disappointed conservatives by frequently siding with the court's liberal minority.
Now the retirement of O'Connor, the first justice to depart in over a decade, has given the right the opportunity to tip the court decisively towards its arch-conservatives, Justices Antonin Scalia and Clarence Thomas. In George Bush, deeply beholden to the religious conservatives, it believes it has a trusty ally. And in O'Connor's retirement, ahead of that of conservative Chief Justice William Rehnquist, expected soon because of his thyroid cancer, it sees a particular significance - while replacing Rehnquist by a "reliable" conservative would merely consolidate the current balance of the court, replacing O'Connor makes possible a decisive shift.
Hence the growing clamour that Mr Bush eschew the chance to appoint his friend, Attorney General Alberto Gonzales, as the first Hispanic on the court. He is regarded with suspicion by the radical right for his views on abortion and on judicial activism. And liberals are preparing for the mother of all confirmation hearings.
De Tocqueville would understand: if all politics ultimately ends up in the courts, in the end, too, judicial appointments will become the ultimate political question. There is much at stake.