Term limits for SCOTUS justices
Scott has blogged on this a few times. I don’t intend to overdraw the current parallels with the situation in 1937 (that’s what the comment thread is for), but I think they’re suggestive.
Also, I was looking at some voting records from the 1970s SCOTUS, and it really is striking the extent to which Stevens was smack in the middle of the Court at that time, while now he’s supposedly a flaming lefty, despite little discernable shift in his views.