The subject here is, specifically, the function of leadership and decision-making ""both within and between"" the twin cities of E1 Paso, Texas, and Ciudad Juarez, Chihuahua, Mexico; more generally, it is the Greek, or at least Aristotelean, ideas of democracy which are under scrutiny. The ""influentials"" refer to those members of the business, political, and professional elites ""whose activities and attitudes in one way or another"" shaped the destinies of those cities during the 1950's. The inspiration for this study was Professor Charles P. Loomis, and he is in fact mostly responsible for the important position which parallel studies of community leadership now occupy in the area of social science research. He should be pleased by this effort since it has quite obviously been exhaustively researched, and yet handled in a way which will not deter the interested non-professional. One hesitates to recommend sweepingly so admittedly limited a project to the general reader, yet Messrs. D'Antonio and Form have produced a book with far reaching implications.