This is a sketch of the development of presidential primaries, and a study of how they are fought and won. It focuses on four recent contests in which the winners--Hoover, Roosevelt, Eisenhower, and Kennedy--used the primaries as a campaign weapon. Presidential primaries occur in less than one-third of the states; this ""patchwork"" system is described and found superior to both the proposed national primary and the old straight- convention mode of nominating. A display of vote-getting strength in a primary can help the aspirant to convert or bypass state leaders and party professionals, expose rivals' weakness, smoke out silent candidates and so forth--to the convention. The author, a political scientist, writes clearly and tersely. His book will appeal to some Making of a President fans, and should not be neglected by serious politiCian-watchers, if only because it inadvertently underlines basic flaws in the electoral process (image-mongering, campaign finances, barriers to independent candidacy, widespread non-voting) which don't seem to bother Professor Davis himself.