How did California Proposition 8 change the state’s marriage law?

California Proposition 8, approved by voters on November 4, 2008, amended the state constitution to define marriage exclusively as a legal union between a man and a woman. This measure effectively overturned a May 2008 California Supreme Court ruling that had legalized same-sex marriage in the state.1234

The passage of Proposition 8 created significant legal uncertainty for the approximately 18,000 same-sex couples who had married during the period between the court's initial legalization and the November election. While the California Supreme Court subsequently upheld the ban in 2009, it ruled that those existing marriages remained valid.134

Proposition 8 was later challenged in federal court, where it was found unconstitutional. In 2013, the U.S. Supreme Court dismissed an appeal regarding the case in Hollingsworth v. Perry, which had the practical effect of letting stand a lower court ruling that the ban was unconstitutional. Following this decision, California resumed issuing marriage licenses to same-sex couples.52