IN THE AFTERMATH of what surely was the most extraordinary presidential campaign ever for the American news media, the Larry King story-like the man himself-has taken on almost mythic proportions: Horatio Alger Makes Good. Real good. Today, the mantle of media greatness rests easy on the selfdescribed "Jewish kid from Brooklyn" in the wake of events that defined the "top banana of talk show hosts" as the undisputed kingmaker of the 1990S. Consider: During the presidential race, Ross Perot announced his candidacy (twice) on "Larry King Live"; after belittling the idea, an uncomfortable (and, finally, desperate) George Bush came on the show late in a losing campaign; and Bill Clinton, mindful of King's role in his victory, promised to be back every six months if he won.