A federal court has invalidated California's ban on same-sex marriage (Proposition 8). The court ruled that the measure violates the Equal Protection Clause and the Due Process Clause of the Fourteenth Amendment. This ruling parallels the Supreme Court ruling in Loving v. Virginia, which invalidated bans on interracial marriage on the same constitutional grounds.
Although Governor Schwarzenegger approves the ruling, Proposition 8 proponents will likely appeal the decision. And while the liberal US Court of Appeals for the Ninth Circuit could possibly uphold the decision, things will become much more difficult for the plaintiffs if the case reaches the Supreme Court. As with most progressive cases, the outcome will likely depend upon how Justice Anthony Kennedy votes.
[Note: This is a breaking news story. I will update it after I have the time to read the opinion more thoroughly. In the meantime, here is a brief summary by Professor David Cruz of USC Law School.]