If Potter Stewart were still alive, he would continue being the same thing he was during his 23-year tenure on the Court -- a very unpredictable swing vote.
didn't Stewart have a very similar record to Stevens in the five and a half terms they were on the court? I remember reading somewhere that Scalia's presence on the court pushed Stevens and O'Connor (and later Souter and Kennedy) away from the conservatives. Being from a similar background to Stevens (i.e. midwestern WASP) - a part of me wonders if Stewart wouldn't have done the same.