Hitherto, Widick says, Detroit was a city of class conflict; now it is ""destined to become a black metropolis."" If white workers attained suburban bliss through trade unionism -- ""one has only to see their homes. . . to realize their stake in society"" -- Negroes are to build an urban utopia on ""a citadel of black political power."" In the '30's workers challenged capital; in the decade of ""color consciousness"" the predominantly black population is ""challenging the white surburbs in every area of public controversy."" The labor struggle of the past is merely a mildewed memory as Widick quickly surveys the mass upsurges of the '30's to prove that ""radicals worked within the framework of viable institutions."" In a final extension of the analogy, the book views the growth of black union caucuses and political machines as a trend paralleling the earlier victories of white workers. The idea that labor ferment is forever extinct among whites may be challenged. And critics may also fault Widick's preference for racially-oriented historical interpretations -- as when in the '30's ""the so-called hillbillies transferred their fanatic allegiance from the KKK to. . . industrial unionism. . . earlier prejudices were erased by class solidarity."" And, given the crescendo of urban fiscal crises and nationwide upheavals in party politics, Widick's emphasis on building a business-as-usual vote-gathering machine for blacks may seem tenable as advocacy but less justifiable as prediction. His analogies and nutshell histories remain too superficial to do justice to this rich and important topic.