Tuesday, a federal appeals court in San Francisco upheld a lower court ruling that California’s ban on gay marriage was unconstitutional. Exactly where this case is headed next was immediately the subject of considerable discussion, but this much is clear: This ruling is yet another small step toward ending legal discrimination based on sexual orientation. It is welcome news.

This has been a convoluted case, with an interesting cast of characters in unexpected alignments. Moreover, while applying only to California, it has an interesting Colorado connection.

This all began in 2008 when California’s state Supreme Court declared unconstitutional two state laws limiting marriage to a man and a woman. Later that year, the state’s voters approved a ballot measure – Proposition 8 – that amended California’s Constitution to reinstate the one-man, one-woman rule, which effectively overruled the court.

Gay marriage proponents – led by former Bush administration Solicitor General Ted Olson – appealed to federal court. There, then-Chief U.S. Judge Vaughn Walker struck down Proposition 8 saying it violated the Constitution’s guarantee of equal protection.

Proposition 8 supporters then challenged both Judge Walker and his ruling. Before that could be heard, however, they had to defend themselves.

When a state law is challenged in court it is typically the state itself that defends it. But California’s governor, then the Republican Arnold Schwarzenegger, refused. Backers of Proposition 8 stepped up to mount the defense themselves, but gay-marriage supporters questioned whether they had the legal standing to do so.

The California state Supreme Court said they did, and the case went to a three-judge panel of the 9th U.S. Circuit Court of Appeals, which issued Tuesday’s ruling. In that it also dismissed claims that Judge Walker was biased in his ruling because he is gay.

That is good news in itself. That a gay man would automatically be suspect is revealing of the thinking behind Proposition 8.

The case could be appealed to the full 11-judge 9th District court or to the Supreme Court. It has long been thought it would end up before the high court.

Seeing the actual ruling, however, a number of legal scholars question whether the Supreme Court would take the case. The ruling is narrowly drawn, does not assert a broad constitutional right to gay marriage, and is limited to California.

What is more, it draws considerably from reasoning and language used by Supreme Court Justice Anthony Kennedy in a 1996 case called Romer vs. Evans. In that case, the high court invalidated a state constitutional amendment – called Amendment 2 – passed by the voters of Colorado in 1992 that banned state or local laws forbidding discrimination on the basis of sexual orientation.

In the process, Amendment 2 struck down existing laws ensuring equal protection, and Kennedy’s opinion in part recognized that in doing so it took away already-won rights. The 9th Circuit saw a parallel in Proposition 8, possibly remembering that thousands of same-sex couples were married in California before its passage. Justice Kennedy is also considered the Supreme Court’s swing vote.

So the legal maneuvering may continue, perhaps for months. Gay marriages are temporarily on hold in California to give all concerned time to sort things out. But as limited as it is, this ruling can only be seen as a step – a small, measured step – toward an end to second-class citizenship for gay and lesbian Americans.