I don't think this is the more feasible potus list for one simple reason: the Democrats were, what looked like, the Presidential party after Roosevelt. The problems with Truman, and the problems with Johnson eventually screwed up that conception. If Dewey manages to take the flack that Truman and the Democrats would have, and things remains stable, I think the likeliest thing is a good Democratic hegemony on the Presidency for some years following Dewey (Stevenson:Kefauver:Kennedy/Johnson/etc:Republican President).