There are two kinds of cases that almost invariably end up before the U.S. Supreme Court — those that turn on fundamental questions of law and liberty, and those contested by implacably determined litigants.

The struggle over Proposition 8, the California initiative that overturned the state high court’s extension of marriage equality to same-sex couples, incorporates both those qualities. That’s why most observers believe that U.S. District Chief Judge Vaughn R. Walker’s ruling Tuesday sooner or later will end up in the black-draped laps of Chief Justice John G. Roberts Jr. and his colleagues.

The crux of Vaughn’s ruling is that “Proposition 8 fails to advance any rational basis in singling out gay men and lesbians for denial of a marriage license. Indeed, the evidence shows Proposition 8 does nothing more than enshrine in the California Constitution the notion that opposite-sex couples are superior to same-sex couples. Because California has no interest in discriminating against gay men and lesbians, and because Proposition 8 prevents California from fulfilling its constitutional obligation to provide marriages on an equal basis, the court concludes that Proposition 8 is unconstitutional.”

Both sides had signaled in advance their intention to appeal if the decision went against them. Proposition 8’s supporters, in fact, already have asked Walker to stay his ruling, which immediately restores marriage equality, pending a decision by the appellate court. Their argument is that if same-sex marriages are allowed to resume and a higher court ultimately overturns Walker’s decision, the consequences will be legally and socially chaotic.

Some opponents of the measure suspect that what Proposition 8’s advocates really fear is the creation of additional facts on the ground. In the months between the California Supreme Court’s recognition of marriage equality as a fundamental right and passage of the measure overturning it, thousands of gay and lesbian couples married. According to estimates based on the U.S. Census, this state has more than 90,000 same-sex couples — the highest number in the nation — and 1 in 5 of those households is raising children.

Each one of those families — for that is what they are in fact, if not always in law — is a walking, breathing rebuttal to the quasi-sociological arguments made by Proposition 8’s defenders in federal court. As Walker noted in his decision Tuesday, this state “has already issued 18,000 marriage licenses to same-sex couples and has not suffered any demonstrated harm as a result.” Californians with open eyes can look around and see the case for marriage equality being made every day in thousands of their neighbors’ homes.

The campaign surrounding Proposition 8 two years ago was the most costly ever waged over a social issue in the history of American politics. Only that year’s presidential candidates raised and spent more money than the $83.2 million expended for and against an initiative that split communities in all sorts of ways. The most striking divide that turned up in most postelectoral analyses — as it does in most national polling — is generational: Most younger Americans, regardless of region, race, ethnicity or religion, consider same-sex marriage a civil rights issue and support it. It’s no comfort to gay and lesbians currently denied the right to marry, but the demographic truth is that time alone will vindicate their struggle for equality.

Moreover, some legal experts, notably Vikram David Amar — a dean at UC Davis’ law school and an authority on federal procedure — aren’t so sure that Walker’s decision inevitably will end up before the Roberts court. A lot depends on which three-judge panel of the U.S. 9th Circuit of Appeals hears the first appeal and, if a rehearing by the entire circuit is asked for and granted, what the composition of that panel will be. If the 9th Circuit’s ultimate ruling does not rely on a broad reading of the 14th Amendment but instead focuses on some language or issue peculiar to Proposition 8 or the California Constitution, some analysts think the Supreme Court might decline to review the decision.

However it unfolds, that process will require years, not months. In the meantime, gay couples will continue to make their case in ways more meaningful than by judicial order — by raising children and living as families.

— Timothy Rutten is a columnist for the Los Angeles Times. He e-mail address is timothy.rutten@latimes.com.