AN EXEMPLARY<br >PRESIDENT?<br >Y THE 1980s the American presidency has become conspicu-<br >ously problematic， devouring its incumbents with appalling regularity.<br >Garter and Ford were both defeated for second-term election bids.<br >After a brief honeymoon， each experienced plunging support， largely<br >because much of the public perceived them as ineffective in the use<br >of their powers. By the end of Reagan s first year， his Gallup poll ap-<br >proval rating dipped to 49 percent and most observers foresaw further<br >troubles ahead as a result of ill-conceived policies. Nixon and Johnson<br >came to grief， because they seemed to carry their policy aims too far.<br >So many Americans felt they had abused presidential power that Nixon<br >resigned to avoid removal by Congress， and Johnson scrapped his re-<br >nomination plans.<br > Kennedy s one thousand days， numbered by assassination rather than<br >unpopularity， initiated a period of ephemeral presidencies. Increasing-<br >ly， the chief executive has become a bird of passage. Not long after<br >taking office， he begins to lose credibility with the domestic and foreign<br >leaders whose cooperation he needs to be effective， because of his prob-<br ><br ><br >