In overturning Roe v. Wade, the Supreme Court delivered the right’s biggest single victory ever, and it may spell the end of the conservative movement as we’ve known it. It was Ronald Reagan who popularized the notion that the conservative movement rested on a fusionist “three-legged stool.” In theory, the three legs were free market economics, national defense and social conservatism. In practice, free market economics meant low taxes and pro-business policies. National defense meant anticommunism and, briefly, the war on terror. Social conservatism covered a lot of territory but the enduring core was opposition to Roe and abortion. Like...