Just hours after a federal appeals court in California issued a ruling that could soon prompt a U.S. Supreme Court showdown over same-sex marriage, Jenner & Block partner Paul Smith had occasion Tuesday to reflect on his role in winning a 2003 opinion from the Court that may well factor into whatever it ultimately decides on the issue.

The opinion in question came out of Lawrence v. Texas, a case in which Houston residents John Geddes Lawrence and Tyron Garner challenged the constitutionality of Texas’s anti-sodomy law after police arrested them in 1998 for allegedly having sex in Lawrence’s home.

Smith, who chairs Jenner’s appellate and Supreme Court practice, handled the case pro bono, argued it before the Court, and by securing a favorable ruling for his clients, invalidated not only the Texas law, but also similar statutes in a dozen other states.

Speaking at Jenner’s New York office Tuesday evening alongside University of Minnesota law professor Dale Carpenter, the author of Flagrant Conduct: The Story of Lawrence v. Texas, Smith said that while such gay rights foes as then-U.S. Senator Rick Santorum were asserting that striking down anti-sodomy laws would inevitably lead to same-sex marriage, he was careful to keep his argument narrowly focused.

“We didn’t want the Court thinking about that,” Smith said at the Tuesday event held to promote Flagrant Conduct, which was published in March. “So we focused on the government leaving you alone, not on validating your relationship.”

Now, with the federal case over the constitutionality of California’s controversial Proposition 8 and a second case concerning same-sex marriage in Massachusetts winding their way to the Supreme Court, Smith acknowledges that Lawrence is likely to come up again.

“The whole theme is that gay relationships are worthy of respect under the law,” said Smith, who became involved in the case via gay rights advocacy group Lambda Legal. “That’s the foundation for the right to marry.”

From start to finish, Lawrence was a “microcosm” of the struggle for gay rights, said Carpenter. Over the years, there had been repeated challenges to anti-sodomy laws in Texas and other states, and in 1986, the Supreme Court had upheld a similar law in Georgia. But the particulars of Lawrence and Garner’s experience encouraged lawyers to mount a fresh challenge, Carpenter said: “Police didn’t usually arrest adults in the privacy of their own home.”

Smith’s argument before the Court was straightforward: the Texas law violated the constitutional right to privacy and discriminated against gay men. By a 6-3 margin, the justices agreed. Moreover, Justice Anthony Kennedy’s majority opinion recognized gay sex as more than just a type of sexual conduct, as it had been considered in the past.

“When sexuality finds overt expression in intimate conduct with another person,” Kennedy wrote, “the conduct can be but one element in a personal bond that is more enduring.”

Flagrant Conduct also reveals an intriguing twist in the story. When Smith stood before the Court in 2003, he was unaware that Lawrence and Garner may never have actually had sex. Carpenter didn’t learn that until he began to delve into the details of the case for what he thought would be a run-of-the-mill law review article on the landmark ruling.

As his research proceeded, Carpenter began to doubt the story as it had been told and retold in court documents and media reports. Not only did Lawrence and Garner deny having sex, he discovered, the arresting officers recounted differing versions of what they saw. Carpenter found parts of the officers’ narratives difficult to fathom—including their claim that Lawrence and Garner would not stop having sex, even when police yelled and drew their guns.

“If you think about it,” Carpenter said, “that would be an incredible feat.”

It’s possible, he said, that the officers hauled Garner and Lawrence to jail as a reaction to the homoerotic decorations in the apartment, but from a legal standpoint, what really happened that night in Houston isn’t important.

“But we owe it to these men,” he added, referring to Lawrence and Garner, both of whom died in recent years, “not to have the police’s version of events be the only version.”