In two canonical decisions of the 1920s--Meyer v. Nebraska and Pierce v. Society of Sisters--the Supreme Court announced that family (including certain relations within it) was an institution falling under the Constitution's protective umbrella. Since then, proponents of "family values" have claimed that a timeless form of family--nuclear and biological--is crucial to the constitutional order. Mark Brandon's new book, however, challenges these claims.

Brandon addresses debates currently roiling America--the regulation of procreation, the roles of women, the education of...