In 2000, 61% of Californians voted to ban equal marriage (although not explicitly in the constitution.) In 2008, 52% of California voters also marked ballots banning equal marriage, this time explicitly in the state constitution, a drop of almost 10 points from 2000.
The trend is clear and, according to a poll released today, support for equal marriage may indeed now be over 50% in California. I haven't had a chance to dissect various aspects of today's Supreme Court ruling, which upholds the ban passed by 52% of voters in November, but allows those same sex couples who married in California last summer to stay married. But I suspect the majority of judges probably made their decision to uphold Proposition 8 long ago, and simply found the legal justification to back up that conclusion.
It always seemed unrealistic that the Court would overrule the wishes of voters. I also do believe that progressive change like this is best achieved through legislatures, not through the courts (although I'll take the courts when politicians often prove too gutless to do the right thing.) For a great analysis by someone who has read the ruling, check out this article.
Today's ruling just means that full equality under the law for LGBT citizens in California is delayed for a couple more years. The next referendum on equal marriage in California, I predict, will go our way.