Opponents of the proposed same-sex marriage ban worry that many black voters, enthused by Senator Barack Obama’s candidacy but traditionally conservative on issues involving homosexuality, could pour into voting stations in record numbers to punch the Obama ticket — and then cast a vote for the marriage ban.

Many of the social measures on the ballots are being pushed by evangelical groups that hope to force Senator John McCain of Arizona, the presumptive Republican presidential nominee, to pay closer attention to their agenda. The proposals that are likely to attract the most attention are same-sex marriage and abortion amendments, along with proposals to ban affirmative action.

Three days after their marriage, Theresa Ramirez filed for divorce, court records show. The court petition says there were “irreconcilable differences” between Ramirez and her partner. The case is one of the first divorces petitions since California legalized same-sex marriage.