These predictions (future national contender) are made about significantly more people than actually make it as national contenders even allowing for a very low standard of what that word means. Virtually anybody who gets like 5% in an early state or is a vice-presidential nomination finalist (the lowest standard possible) gets this sort of talk.
Yes indeed. Back then, basically any prominent southern Democrat got it, and I recall Bumpers, Gore, and Bill Clinton all getting their turn. On the R side, such predictions have been made for luminaries such as Jindal, Rubio, Coleman, Giuliani, Lingle, and Ryan (but I believe, not for Trump).