Where the vice-presidency is concerned, there may be a story in the offing: Jimmy Carter did give unprecedented responsibility to Walter Mondale--and certainly the perils of the modern presidency suggest a closer look at who's fit to be v-p. But both the old powerlessness of the office, and its new potential, are smothered here in bland, mealy-mouthed words--sometimes internally contradictory, sometimes contrary to fact. ""The vice-president,"" says Hoopes in the first sentence, ""is one of the most powerful and important leaders in the nation""; further down the page, he notes that, ""from the earliest days of our country, the office was considered unimportant and a sure way for a public official to disappear into obscurity."" Since Truman succeeded to the presidency after FDR's death, we're told, ""the concept of the job has gradually changed. With few exceptions, the men who've held the office were carefully selected by the presidential candidates as men who might someday succeed them."" Alben Barkley? Richard Nixon? Spiro Agnew? even George Bush? Anyone conversant with the political considerations governing those choices knows how hollow that assertion is. The body of the book consists of brief biographies--first, of the 13 vice-presidents who succeeded to the presidency, then of the remainder. These are mostly dry, date-studded dossiers of no conceivable interest except as substitutes for the encyclopedia. Of major or recent figures, somewhat more is told--in a very cautious way. We hear, for instance, that Henry Wallace ""was considered something of a radical""--but not the reason why (and as for the ""Progressive Party""--well, he headed its ticket). Two brief concluding chapters sketch in--along similar shaky-to-controvertible lines--""the development of the vice-presidency."" Close to half the book, meanwhile, consists of pictures--portraits of the lot, stock photos of recent incumbents getting off planes, speaking, conferring, and such. Some hard facts aside, this is a repository of pseudo-information that even wised-up kids will see through.