FRESH AIR: Of all the moral subjects and ethical rules elaborated throughout the Bible and the history of Christianity, why have so many American Christians seemed disproportionately obsessed with sex? And how has that obsession divided America? These are the questions that led my guest, R. Marie Griffith, to write her new book, “Moral Combat: How Sex Divided American Christians And Fractured American Politics.” She writes about the battles over women’s suffrage, birth control, interracial marriage, sex education, abortion, sexual harassment and marriage equality. The book ends with the Women’s March following Trump’s inauguration. Griffith grew up in a Baptist family during the rise of the religious right. She’s a professor of religion and politics at Washington University in St. Louis, where she directs the Danforth Center on Religion and Politics. MORE