A thoughtful but short-sighted study of a precariously splintered American Jewry. Wertheimer (Unwelcome Strangers, 1987) uses his background history professor at the Jewish Theological Seminary (Conservative) to offer more than sociological insights in reading several generations' worth of statistics on American Jewish patterns of religious practice and identification. Nonetheless, with his study anchored in the 40's and 50's--boom years for the Conservative movement--there's a strong tilt toward his own denomination. Wertheimer too often positions the Conservative movement as true ``American Judaism,'' and, by not drawing the longer shadows of Reform and Orthodox Judaism, he fails to credit the Reform for initiating a Judaism for nonpracticing American Jews. Moreover, instead of wondering whether ``Orthodoxy can be viewed as a coherent and united movement,'' he should have made the point that traditional Judaism is unchanged since the days of the Pharisees. To survive suburbanization, the Conservatives in 1950 decided to allow driving to synagogue on the Sabbath--forfeiting any fealty to biblical law. Wertheimer doesn't mark this milestone as the philosophical demise of the movement, although, to his credit, he concedes that Conservative Judaism is ``caught in a cross fire...and hard pressed to justify its centrism.'' He shows the Conservative sun as setting and the inclusiveness of the Reform and Reconstructionists as instrumental in slowing rampant loss from intermarriage and assimilation. But for all of Wertheimer's statistics and trend-watching, the high birth and emigration rates of the Orthodox are ignored. The author is at his strongest when comparing the rises and falls of Jewish to Christian denominations, and when discussing how the various movements reacted to the sexual revolution, the women's movement, and the era of personal, nontraditional spiritual searching that began in the late 60's. Extensive notes and bibliography add to the value of this study for the student of religion, but it lacks the punchy thesis needed for more popular appeal.