I hear talk about how the office of Solicitor General is some sort of steppingstone to the Supreme Court.
Is it? A desultory Google is inconclusive, but I can think of a few examples and the record seems not very instructive.
The most recent example, I believe, would be Kagan's own mentor, Thurgood Marshall. I happily number myself among the ranks of Marshall admirers; I remember watching him argue (I think it was Miranda), and it was quite a sight: big hulking guy in a morning coat with the easy manner of a seasoned litigator -- "that's exactly what I mean, your honor," he said to somebody about somethin g.
Two more: Robert Jackson and Stanley Reed. In other respects also, you can bracket these two together: both old-fashioned country lawyers (the last two justices not to graduate from law school;); both New Deal partisans. Jackson was a superb writer, one of the few really good ones ever to sit on the bench. Both surely counted as liberals by the standards of their time but their record appears more equivocal in retrospect.
There most be others but that's all I can think of at the moment. Oh, but then there is this guy.