From the day the Pilgrims stepped off the Mayflower, religion has played a prominent role in American public life. The faithful have been vital participants in nearly every major social movement in U.S. history, progressive as well as conservative. Still, the close intertwining of religion and politics in the last 40 years is unusual, especially in the degree of the politicization of religion itself. Indeed, religion's influence on U.S. politics has hit a high-water mark, especially on the right. Yet at the same time, its role in Americans' personal lives is ebbing. As religion and politics have become entangled, many Americans, especially younger ones, have pulled away from religion. And that correlation turns out to be causal, not coincidental.