In 2000, the citizens of California passed Proposition 22, which affirmed a legal understanding that marriage was a union between one man and one woman. In 2008, the California Supreme Court held that the California Constitution required the term “marriage” to include the union of same-sex couples and invalidated Proposition 22. Later in 2008, California citizens passed Proposition 8, which amended the California Constitution to provide that “only marriage between a man and a woman is valid or recognized by California.” The respondents, a gay couple and a lesbian couple, sued the state officials responsible for the enforcement of California’s marriage laws and claimed that Proposition 8 violated their Fourteenth Amendment right to equal protection of the law. When the state officials originally named in the suit informed the district court that they could not defend Proposition 8, the petitioners, official proponents of the measure, intervened to defend it. The district court held that Proposition 8 violated the Constitution, and the U.S. Court of Appeals for the Ninth Circuit affirmed.