When Louise Trubek and her husband, Dave, drove from New Haven to Washington to listen to oral arguments before the Supreme Court in Trubek v. Ullman, she was pregnant. The Trubeks had met at the University of Wisconsin, Madison, and married in 1958. The next year, while they were both students at Yale Law School, they filed a complaint against the State of Connecticut about a statute that prevented their physician, C. Lee Buxton, the chief of obstetrics and gynecology at Yale Medical School, from discussing contraception with them. They wanted to have children one day, according to the complaint, but “a pregnancy at this time would mean a disruption of Mrs. Trubek’s professional education.” By the time that Trubek v. Ullman reached the Supreme Court, in the spring of 1961, Louise Trubek had graduated from law school and was ready to start a family. The case was dismissed, without explanation.

This spring marks the fiftieth anniversary of the case that went forward instead: Griswold v. Connecticut. (“We became the footnote to the footnote,” Trubek told me.) In Griswold, decided in June, 1965, the Supreme Court ruled 7–2 that Connecticut’s ban on contraception was unconstitutional, not on the ground of a woman’s right to determine the timing and the number of her pregnancies but on the ground of a married couple’s right to privacy. “We deal with a right of privacy older than the Bill of Rights,” Justice William O. Douglas wrote in the majority opinion. “Marriage is a coming together for better or for worse, hopefully enduring, and intimate to the degree of being sacred.”

In the half century since Griswold, Douglas’s arguments about privacy and marriage have been the signal influence on a series of landmark Supreme Court decisions. In 1972, Eisenstadt v. Baird extended Griswold’s notion of privacy from married couples to individuals. “If the right of privacy means anything,” Justice William Brennan wrote, “it is the right of the individual, married or single, to be free from unwarranted governmental intrusion into matters so fundamentally affecting a person as the decision whether to bear or beget a child.” Griswold informed Roe v. Wade, in 1973, the Court finding that the “right of privacy . . . is broad enough to encompass a woman’s decision whether or not to terminate her pregnancy.” And in Lawrence v. Texas, in 2003, Justice Anthony Kennedy, writing a 6–3 decision overturning a ban on sodomy, described Griswold as “the most pertinent beginning point” for the Court’s line of reasoning: the generative case.

A few weeks ago, the Supreme Court heard oral arguments in Obergefell v. Hodges, a consolidation of the petitions of four couples seeking relief from state same-sex-marriage bans in Kentucky, Michigan, Ohio, and Tennessee. The federal Defense of Marriage Act was struck down by the Court in 2013, in U.S. v. Windsor, a ruling in which Kennedy cited and quoted his opinion in Lawrence. But bans still stand in thirteen states. In 2004, Ohio passed a law stating that “only a union between one man and one woman may be a marriage valid in or recognized by this state.” The Ohioans James Obergefell and John Arthur had been together for nearly twenty years when Arthur was diagnosed with A.L.S., in 2011. In 2013, they flew to Maryland, a state without a same-sex-marriage ban, and were married on the tarmac. Arthur died three months later, at the age of forty-eight. To his widower, he was, under Ohio law, a stranger. The Court is expected to issue a ruling in June.

The coincidence of the fiftieth anniversary of the Court’s ruling in Griswold and its anticipated decision in Obergefell makes this, inescapably, an occasion for considering the past half century of legal reasoning about reproductive and gay rights. The cases that link Griswold to Obergefell are the product of political movements that have been closely allied, both philosophically and historically. That sex and marriage can be separated from reproduction is fundamental to both movements, and to their legal claims. Still, there’s a difference between the arguments of political movements and appeals to the Constitution. Good political arguments are expansive: they broaden and deepen the understanding of citizens and of legislators. Bad political arguments are as frothy as soapsuds: they get bigger and bigger, until they pop. But both good and bad constitutional arguments are more like blown-in insulation: they fill every last nook of a very cramped space, and then they harden. Over time, arguments based on a right to privacy have tended to weaken and crack; arguments based on equality have grown only stronger. ...