WILLIAM H. Rehnquist was one of the great chief justices in American history. Over the last three decades, he moved the Supreme Court in a more conservative direction, advancing states' rights, expanding police powers and returning the country to its Tocquevillian roots. But in recent years his colleagues have handed him a series of setbacks in areas dear to him — including religion, property rights, federalism and capital punishment — signaling that perhaps the time had come for fresh leadership. Leading the court is a notorious challenge. Justices are a famously independent bunch. A chief justice cannot order his colleagues...