The ruling this week by the California Supreme Court upholding Proposition 8’s same-sex marriage ban sent thousands into the streets of San Francisco, Los Angeles and dozens of cities across the country to protest. Long-time activist Robin Tyler, who was a plaintiff in last year’s successful suit challenging the state’s same-sex marriage ban and the unsuccessful legal attack this year on Proposition 8, did not mince words.

“The upholding of Proposition 8 by the court is a cowardly retreat from the pro-equality stance it took last year,” said Tyler, “and makes our state a laggard behind pro-equality states like Iowa and most New England states.”

The reason for her frustration is obvious enough. A little more than one year ago, the California High Court struck down a ballot initiative banning same-sex marriage as a bias-motivated measure that violated equal protection under the law and impinged on a “fundamental right” guaranteed by the state’s Constitution. Six months later, an almost identical ballot initiative called Proposition 8, adopted by an even smaller margin of votes, snatched away that “fundamental right.”

Confronted with such a naked power play – a bare majority re-adopting the same ballot initiative found unconstitutional a year earlier – the California Supreme Court this week just shrugged its shoulders. “There’s nothing we can do,” the 6-1 majority said, essentially. “It’s just really easy to amend our Constitution.”

That’s really what the challenge to Prop. 8 came down to – the very same simple majority of California voters that can adopt a state statute by proposition can also amend the state’s Constitution by proposition. It’s a huge flaw in the constitutional design of our most populous and influential state.

If individual rights are to be protected from majority abuse, then trampling on a minority should obviously require something more than a simple majority of voters. That’s why the U.S. Constitution and the founding documents of the vast majority of other states don’t let amendments go before the voters at all, or only after they are pre-approved by a legislature, usually by super-majority and often over successive sessions.

The gay plaintiffs challenging Prop. 8, backed by state Attorney General Jerry Brown, tried their best to make an end-run around the easy amendability of the California Constitution, honing in on archaic language that says “amendments” can go before voters but “revisions” have to get the Legislature’s OK first.

Parsing through the difference between an “amendment” and a “revision” is the kind of thing that earns lawyers the revulsion of right-thinking people everywhere. In this case, the court majority got the better of the argument, pointing to an uninterrupted chain of earlier court rulings about what amounts to a “revision.”

Despite the best pro-gay efforts of some very smart lawyers, calling Prop. 8 a “revision” rather than an “amendment” would require ramming a very square peg down a very round hole.

It’s very cold comfort, of course, to know that the justices weren’t simply cowardly fearing recall by voters – another fundamental flaw in California’s legal system – when they upheld Proposition 8; just like it’s pretty cold comfort that the court didn’t forcibly divorce the 18,000 same-sex couples who married before Prop. 8 passed.

Still, the news isn’t all bad. Politically speaking, it will be much better for the gay rights movement in the long haul to repeal Prop. 8 at the ballot box, rather than from the bench. Equality California has already announced plans to put a pro-gay proposition – call it Prop Anti-8 – on the 2010 ballot, and this week’s court ruling has at least energized volunteers.

What’s more, this temporary defeat may actually turn into the mother of all victories for same-sex marriage. One day after the Prop. 8 ruling, two of the country’s most prominent lawyers, who just so happened to be on opposite sides of the Bush vs. Gore case back in 2000, have come together to file a federal lawsuit challenging the measure.

These two strange same-sex bedfellows include Ted Olson, a conservative hero as George W. Bush’s lawyer back in 2000 and subsequently solicitor general for W.’s first term, along with David Boies, Al Gore’s lawyer and the guy who took on Microsoft back in the ’90s for the Clinton Justice Department. Their Proposition 8 suit is based on the guarantees of equal protection and due process in the U.S. Constitution, and if successful would in domino fashion strike down same-sex marriage bans everywhere, along with DOMA, the federal Defense of Marriage Act.