Lost in the debate about the nomination of Judge Samuel A. Alito Jr. to the Supreme Court is a critical fact: Through appointments to the federal appellate courts, the conservatives already have largely won the judicial revolution.

The Supreme Court ordinarily does not take a case to affirm lower court decisions. Since the late 1960s, Republican presidents have ensured that federal appellate court judges stand firmly in the conservative camp. While the Supreme Court decides approximately 80 cases a year, the federal appellate courts decide thousands.

The judicial landscape is remarkably different than it was in the heyday of the Warren Court. Then, for example, federal appeals courts such as the D.C. Circuit or the 5th Circuit in the South were in the forefront of liberal judicial thought. Today, the majorities on these courts are solidly conservative. Thus there is less need for a conservative Supreme Court to hold the lower courts in check.

This doesn't mean that the Supreme Court is irrelevant. It can reverse precedent that must be treated as binding by lower federal courts (read: Roe v. Wade), and it hears appeals from state courts in which constitutional questions are raised. But outside these relatively narrow, though important, classes of cases, one should not expect that the elevation of Judge Alito to the Supreme Court would make much difference to the basic direction of American law. The federal appeals courts will ensure that this direction remains conservative for decades.