The title implies that the President's political expertise is under review. No one would be in a better position than Mr. White to provide such a review. As the former political essayist for Harper's magazine and the author of the Citadel, an analysis of the Senate, his advantages also include a personal friendship dating back 30 years. Strangely enough, the advantages seem to become handicaps. It isn't just the tone of admiration that pervades the text. This is understandable, particularly in the light of the Citadel, where the author revealed his respect for the politicians who could produce workable legislation through grand strategy, nature compromise and enlightened self-interest, for this exactly typifies Lyndon Johnson as Senate Majority Leader. Rather, it is the tone of ""I-could-a-tale-unfold-if-I-but-chose."" Mr. White admires the President for ignoring the slights of the ""Kennedy Palace Guard"" or the criticisms of opponents, but for a biographer to mention these affairs and so many others without giving the details or names (which magazines have not hesitated to use) is a supreme reader irritant. In discussing the President's senatorial career, only a few specific issues are discussed and his Senate colleagues are massed together as the ""right,"" the ""left,"" etc. -- faceless keys with Johnson at the grand console. The bid for the Presidency against Kennedy is hardly touched on; the family background and education has received fuller coverage in recent juvenile titles; and altogether, it is a book about a man who deserves better by a man who can do better.