[JURIST] Thousands of demonstrators in San Diego and Los Angeles on Saturday protested [Union-Tribune report] the passage [unofficial results; JURIST report] of Proposition 8 [text and materials], an amendment to the California constitution [text] making same-sex marriages illegal in the state. The proposition, approved by about 52 percent of California voters last week, provides that "[o]nly marriage between a man and a woman is valid or recognized in California." Earlier in the week, similar protests [AP report] were held in San Francisco, and also in Utah, where protesters picketed outside of the headquarters of the Mormon Church [religious website], which had supported the proposition [press release]. Also last week, advocacy groups American Civil Liberties Union (ACLU), Lambda Legal and the National Center for Lesbian Rights filed a writ petition [PDF text; JURIST report] with the California Supreme Court [official website] seeking to invalidate the amendment. An estimated 2.7 million not-yet-counted provisional and absentee ballots on the measure are not expected [LA Times report] to change the result of the vote on the proposition. AP has more.

Proposition 8 was a response to the California Supreme Court's decision in May striking down [JURIST report] a statutory ban on same-sex marriage as violating the equal protection and privacy provisions of the state constitution. The measure generated more than $60 million in contributions [JURIST report] to committees representing both sides of the issue – a figure believed to be a US record. Voters in Arizona [Proposition 102 text, PDF] and Florida [Proposed Constitutional Amendment 2 text, PDF] also approved [JURIST report] similar measures last week. More than half of US states have adopted constitutional amendments [NCSL list] limiting marriage to opposite-sex couples, while most of the remainder have defined marriage by statute. Massachusetts and Connecticut [JURIST reports] are now the only US states that sanction same-sex marriages under decisions by their highest courts.