One hundred and twenty years ago, the Congress of the United States was embroiled in a debate over how best to regulate a type of marriage that appalled most Americans. Republicans were making political capital out of their vigorous and vitriolic attacks against the idea of such marriages, while Democrats were looking for a way to finesse the issue to maintain the political support of the unpopular minority believing in such marriages without offending the majority. Laws were introduced and passed prohibiting these marriages. Fearing that a law would be insufficient, however, a constitutional amendment was proposed to ban such marriages. The Supreme Court upheld the right of states to criminalize such marriages, though it was never asked to rule on the right of a state to recognize such marriages. Persons wishing to enter such marriages were advised to go to a neighboring country that would recognize the legitimacy of their unions. In the 1880s, the issue was polygamy, the unpopular minority Mormons, and the neighboring country Mexico (see Edward L. Lyman, Political Deliverance, 1986). Today same-sex marriages between gays or lesbians, some marrying in Canada, are causing as much turmoil in Congress as the issue of polygamy did then.

Evan Gerstmann provides us with a readable and thought-provoking analysis of the constitutional issues involved in the question of same-sex marriages. Written prior to the Supreme Court decision in Lawrence v. Texas, though he notes the case in the preface, and before the Massachusetts Supreme Judicial Court announced it could find no justification for denying the right to marry to same-sex couples in its state constitution, the arguments in this book continue to have relevance. In his opening sentence, Gerstmann makes clear that he will be arguing that the right of same-sex couples to marry is a “fundamental constitutional right” (p. 3) built on the right of all citizens to equal protection under the law as outlined in the Fourteenth Amendment despite, he says, an original plan to write “a book against courts requiring states to recognize same-sex marriage” (p. 10). The book itself both shows the path he took to this conclusion and identifies and refutes competing analyses that conclude that same-sex marriages can be legally prohibited.

The author starts by getting rid of the term (and concept) “gay rights,” arguing instead that there are only fundamental rights for all citizens, and should the state wish to deny a particular right to any citizen or group of citizens, it must produce a compelling reason. He is unwilling to try to shoehorn gay men and lesbians into a “protected class” and generally disparages the approach of classifying people into groups for which the denial of rights is subject to varying levels of scrutiny, depending on which group is at issue. The author concludes that the Supreme Court's jurisprudence in the area of equal protection is, to be blunt, a disastrous muddle of unclear opinions.

And what reasons do opponents of same-sex marriage offer in support of denying access to the institution of marriage? Gerstmann identifies four categories: “1) definition, tradition, and religion; 2) natural law; 3) the equation of marriage with procreation and child-rearing; and 4) moral disapproval of homosexuality” (p. 19). He outlines the arguments made in each category and then assesses the strength of each as a reason to deny a fundamental right to a group of citizens, and he finds them wanting. To the possible dismay of supporters of same-sex marriage, on the other hand, he also criticizes the effort to equate the denial of the right to marry a same-sex partner with sex or gender discrimination. He argues that the analogy between antimiscegenation laws and anti-same-sex marriage laws is misplaced; the former laws were clearly an element in a social system of white supremacy, while it is not clear which sex is being discriminated against when same-sex marriages are being prohibited. Some might disagree with this reasoning, finding that the denial of the right of gay men or lesbians to marry same-sex partners supports patriarchal systems not unlike racist systems of the mid–twentieth century, but that is a strength of this book: The arguments are laid out clearly and so it is easy to determine where and why you disagree with the author.

Much of Same-Sex Marriage and the Constitution is a review of cases that, in the author's view, establish clearly that the right to marry is a fundamental right. With the addition of the Lawrence decision in 2003, his argument becomes even stronger. He would agree with Justice Scalia's dissent in the case that it is not unreasonable to expect future courts to use Lawrence to find a right to marry someone of the same sex in the future. He also shows that the right to marry has not historically been limited to persons with the ability to procreate and agrees with same-sex marriage opponents that identifying marriage as a fundamental right could lead to incestuous (adult) marriages and polygamy. There may be reasons to ban each, but he argues persuasively that you cannot just say “because it has always been that way” or because it offends the moral teachings of a particular religion.

In the concluding chapter, “Principles and Practicalities,” the author's preference for principles comes through quite clearly. He recognizes that many legal scholars and, until the last year or so, many gay and lesbian activists had focused on achieving a legal status somewhat less than full marriage rights—civil unions, domestic partnerships, reciprocal beneficiaries, and so on. Gerstmann disagrees with the “half-loaf” approach and insists that nothing less than full marriage equality should be acceptable under the U.S. Constitution. That he would like this goal achieved by using only principled arguments and avoiding what he sees as the false analogy with antimiscegenation laws is also clear. But, of course, the Constitution can be changed and activists for and against same-sex marriage are preparing to do battle over an amendment at this very moment. Both sides must agree with Gerstmann: The Constitution today does protect the right to marry whomever you choose.