SEX education has been the Middle East of the culture wars and one of the longest-running, most rancorous battlegrounds of American social policy. For nearly 40 years, conservatives—many of them, though by no means all, observant Catholics and fundamentalist Christians—have been battling the increasing presence in the public schools of a permissive strain of sex education that came to be known as “comprehensive sexuality education.” Unlike sex-ed programs from the first half of the twentieth century that had frowned on teen sex, comprehensive sexuality education affected a morally neutral or even positive stance toward adolescent sexual activity, supporting what was usually described as teenagers’ “autonomous decision making,” and promoting their use of contraception.