For those late to the game, the infamous ballot measure was passed by voters in November 2008, reinstating a ban on gay marriage six months after the state's Supreme Court rejected it on constitutional grounds. Its passage led to a three-year legal showdown.
After the vote passed, two same-sex couples filed a lawsuit in federal court contending that Prop. 8 violates the Constitution. In February, a three-judge panel agreed that the ban was unconstitutional, but anti-gay marriage activists pushed the appeals court for an 11-judge panel to rehear the case, which was denied.
This is just the latest boost for marriage equality advocates. Following President Obama stepping up in support of same-sex nuptials last month, last week a U.S. appeals court in Boston struck down a key part of the Federal Defense of Marriage Act, which defines marriage as solely between a man and a woman.
