On Wednesday, November 5, 2008, three lawsuits were filed, challenging the validity of Proposition 8 on the grounds that revoking the right of same-sex couples to marry was a constitutional "revision" rather than an "amendment", and therefore required the prior approval of two-thirds of each house of the California State Legislature. Plaintiffs in the various suits included same-sex couples who had married or planned to marry, the cities of San Francisco and Los Angeles and the county of Santa Clara. The California Supreme Court heard several challenges to Proposition 8 and on May 26, 2009, upheld the proposition but did not overturn previous same-sex marriages which occurred following their ruling in June 2008 and before the day following the November 4 election.