Robert Mullen's relationship with the leaders of The Church of Jesus Christ of Latter-day Saints began in 1955 when he handled the publicity for the Tabernacle Choir's first European tour. The LDS Church, which grew from six members in 1830 to two million in 1960, is today (with 12,000 missionaries at work in 65 countries) one of the fastest-growing religious groups, and now faces the prospect of a member--Governor Romney--being a serious contender for the American Presidency. This condition has engendered much journalistic and political interest in Mormonism, and so we have the second book on the LDS within a few weeks. Wallace Turner's The Mormon Establishment (see p. 803) left much to be desired in terms of actual hard facts and figures: Turner complained that Church leaders were unresponsive to his requests for economic and other specific data. Mullen has had the advantage of being closer to his sources, and his is a much better-balanced book, with a full analysis of the original and continuing appeal of the sect to its followers, more historical material, and substantial economic and financial data. Turner's book pivots (if obliquely) on a single issue--the Church's theological mark-of-Cain doctrine regarding Negroes, its actual practices toward them, and the meaning of those practices for America and Gov. Romney in the Civil Rights Era. Mullen speaks only briefly of Negroes in connection with the Church, and it is not easy for a non-Mormon to guess which author's position more nearly mirrors the true situation. Both books are bound to find partisans and be widely discussed if Romney's candidacy actually does take shape. Halftones.