They are not exactly father and son, but they share a singular bond in an elite business: 25 years ago this summer, almost exactly half his lifetime ago, John G. Roberts went to work for William H. Rehnquist, and now he stands poised to become the first Supreme Court clerk in American history to sit on the bench alongside the justice he served.

His 13 months in the chambers of Justice Rehnquist spanned the period of the 1980 election and the dawn of the Reagan revolution in Washington. It was a heady time of relentless work, long walks on Capitol Hill discussing cases informally with the justice and sharp-elbowed basketball games in the Supreme Court gym, wryly referred to as the "highest court in the land."

It was a time when the Supreme Court was far different, more liberal, and that made John Roberts stand out among the other clerks.

"John's conservatism was in fact a sign of intellectual courage, coming out of Harvard and being surrounded by law clerks from mainly liberal, East Coast, Ivy institutions," said John A. Siliciano, a law professor at Cornell who clerked for Justice Thurgood Marshall at the same time.