The 9th U.S. Court of Appeals, headquartered in San Francisco, is considered the most liberal of the 13 federal courts of appeal in the United States.
But what about the U.S. Supreme Court, where this or a similar future case is inevitably headed, where moderate conservative Justice Anthony Kennedy holds sway?
Any number of analyses show Kennedy voting in the majority in more than 90 percent of cases, more than any other justice. He votes mostly with the conservative bloc. Frequently, he is the pivot around which the four other conservative justices swing, often writing the majority opinion in 5-4 decisions.
Kennedy, 72, is a Roman Catholic, like all the other conservative justices on the high court.
So assuming the injunction survives argument in the 9th Circuit, will it be shot down in flames by the Supreme Court?
Judging by the past, maybe not.
At the core of the California case, as in many cases before the Supreme Court, is the 14th Amendment to the U.S. Constitution. The amendment was adopted in 1868 in part to keep the states from depriving freed slaves of citizenship.
Sections 1 and 5 are the ones most relevant to modern times. Section 1 contains the "citizenship clause," ("All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the state wherein they reside" -- now criticized by Republican senators because it makes U.S. born children of illegal immigrants U.S. citizens); the "due process clause" (which guarantees fair treatment under the law) and the "equal protection clause" (which guarantees equal treatment under the law).
Section 5 gives Congress the authority to enforce the amendment, and for that matter, the Bill of Rights.
Back to the California case, voters in November 2008 approved the same sex marriage ban -- Proposition 8 -- by a 52.3 percent majority six months after the California Supreme Court ruled that same-sex marriage was permitted under the state Constitution. That same state court later upheld Prop 8 as a valid amendment to the state Constitution.
But on Aug. 4, in a case brought by two gay couples, U.S. District Chief Judge Vaughn R. Walker issued a preliminary injunction against the ban, saying it "both unconstitutionally burdens the exercise of the fundamental right to marry and creates an irrational classification on the basis of sexual orientation."
Supporters of Prop 8 appealed, and Walker stayed his order until next Wednesday pending action by the appeals court. At the same time, he suggested the appeal by proponents could founder at the 9th Circuit because state officials are not involved in it.
In fact, it is conceivable that both the appeals court and the U.S. Supreme Court could rule that the private sponsors of Prop 8 do not have the standing to appeal Walker's ruling, only state officials do. Since California officials are not supporting Prop 8, Walker might end up with the last word until some similar case pops up.
But assuming the high court agrees to hear the case or some similar future case, what Supreme Court jurisprudence points to how the high court might rule?
In 1996 the U.S. Supreme Court ruled in a similar case -- Romer vs. Evans, involving a voter-enacted amendment to a state constitution that attempted to limit the rights of gays and lesbians.
Several Colorado communities, including liberal Aspen, had passed ordinances banning discrimination based on sexual orientation. In reaction, Colorado voters, in a statewide referendum, adopted "Amendment 2" to the state Constitution.
"Amendment 2" struck down the local ordinances, and further, prohibited any action at all levels of government designed to protect people based on their "homosexual, lesbian or bisexual orientation, conduct, practices or relationships."
The Colorado Supreme Court upheld a judge's injunction against enforcement of the amendment. Eventually, the U.S. Supreme Court agreed in a 6-3 decision that said the Colorado law violated the equal protection clause of the U.S. Constitution's 14th Amendment.
Kennedy was a relatively junior member of the court -- he was appointed to the Supreme Court by President Ronald Reagan in 1988 -- when he wrote the majority opinion in Romer.
"One century ago, the first Justice (John Marshall) Harlan admonished this court that the (U.S.) Constitution 'neither knows nor tolerates classes among citizens," Kennedy said. "Unheeded then (in dissent), those words now are understood to state a commitment to the law's neutrality where the rights of persons are at stake. The equal protection clause enforces this principle and today requires us to hold invalid a provision of Colorado's Constitution."
Kennedy cited what he considers Colorado's rather lame justifications for the law, and said, "The breadth of the (Colorado) amendment is so far removed from these particular justifications that we find it impossible to credit them. We cannot say that Amendment 2 is directed to any identifiable legitimate purpose or discrete objective. It is a status-based enactment divorced from any factual context from which we could discern a relationship to legitimate state interests; it is a classification of persons undertaken for its own sake, something the equal protection clause does not permit."
He added, "We must conclude that Amendment 2 classifies homosexuals not to further a proper legislative end but to make them unequal to everyone else. This Colorado cannot do. A state cannot so deem a class of persons a stranger to its laws."
In dissent, Justice Antonin Scalia expanded upon his "kulturkampf," or culture war, theme. "The court (majority) has mistaken a kulturkampf for a fit of spite. The constitutional amendment before us here is not the manifestation of a 'bare ... desire to harm' homosexuals," he said, "but is rather a modest attempt by seemingly tolerant Coloradans to preserve traditional sexual mores against the efforts of a politically powerful minority to revise those mores through use of the laws."
In 2003, the U.S. Supreme Court handed down an even more startling decision on the rights of homosexuals.
In Lawrence vs. Texas, the justices in a 6-3 decision struck down the Lone Star State's sodomy ban, saying it violated the due process clause.
Writing in the majority opinion, Kennedy essentially told government at all levels it had no business in the bedroom, and argued the Constitution is a living organism that can apply to the 21st century, not just the 18th and 19th centuries.
"Liberty protects the person from unwarranted government intrusions into a dwelling or other private places," Kennedy wrote. "In our tradition the state is not omnipresent in the home. And there are other spheres of our lives and existence, outside the home, where the state should not be a dominant presence. Freedom extends beyond spatial bounds. Liberty presumes an autonomy of self that includes freedom of thought, belief, expression and certain intimate conduct. The instant case involves liberty of the person both in its spatial and more transcendent dimensions."
He added: "Had those who drew and ratified the due process clauses of the Fifth Amendment or the 14th Amendment known the components of liberty in its manifold possibilities, they might have been more specific. They did not presume to have this insight. They knew times can blind us to certain truths and later generations can see that laws once thought necessary and proper in fact serve only to oppress. As the Constitution endures, persons in every generation can invoke its principles in their own search for greater freedom."
Brave, inspiring words, but are they enough to lead Kennedy, and the four-member liberal bloc that sometimes joins him on the nine-member court, to rule that same sex marriage is a constitutional right?
Or will they pull back from the brink, concerned that the enshrinement of same sex marriage among the civil rights of this country would constitute a shocking disruption of public life.
Time may tell.