PROPOSITIONS:CALIFORNIA VOTERS voted to reintroduce a ban on gay marriage, casting doubt over the unions of some 18,000 same-sex couples who married over the last four months.
The controversial initiative, which would rewrite the state's constitution to overturn the right to same-sex marriage granted by the California Supreme Court in May, was leading with 52 per cent of the vote, with 91 per cent of precincts reporting results.
Groups on both sides are estimated to have spent some $73 million (€55.8 million) during the fraught "Proposition 8" campaign.
If passed, it will be the first time a vote to ban gay marriage has taken place in a state where such unions are already legal. A ban was approved in Arizona and a similar measure looked set to pass in Florida. According to California exit polls, blacks were far more likely than whites or Hispanics to support the marriage ban.
Age was also a key factor - the exit polls showed voters under 30 opposing the ban by a 2-to-1 ratio, while most voters 60 and older supported the ban. President-elect Barack Obama opposed the California amendment and endorses the concept of broader rights for same-sex couples.
Among the other ballot initiatives put before the electorate in some states on Tuesday, voters in Arkansas approved a measure banning unmarried couples from serving as adoptive or foster parents. Supporters made clear their main target was gays and lesbians.
Ballot initiatives are allowed in 36 of the 50 states, and a simple majority is required for a proposal to become law. This year there were 153 state-wide ballot initiatives, addressing issues including tax, transport, gambling and energy. California's Proposition 4, which would require doctors to notify parents or guardians when minors seek an abortion, appeared to be headed for defeat. California voters defeated similar initiatives twice before, in 2005 and 2006.
Voters in Colorado and South Dakota rejected ballot measures that could have led to sweeping bans of abortion, and Washington became only the second state - after Oregon - to offer terminally ill people the option of physician-assisted suicide. A measure in Colorado, which was defeated soundly, would have defined life as beginning at conception.
Its opponents said the proposal could lead to the outlawing of some types of birth control, as well as abortion.
The South Dakota measure would have banned abortions except in cases of rape, incest and serious health threat to the mother. A tougher version, without the rape and incest exceptions, lost in 2006.
Elsewhere, the marijuana reform movement won two victories, with Massachusetts voters decriminalising possession of small amounts of the drug and Michigan joining 12 other states in allowing its use for medical purposes.
From now on, people caught in Massachusetts with an ounce or less of pot will no longer face criminal penalties. Instead, they'll forfeit the marijuana and pay a $100 civil fine. The Michigan measure will allow severely ill patients to register with the state and legally buy, grow and use small amounts of marijuana to relieve pain, nausea, appetite loss and other symptoms.
In San Francisco, another local measure - to halt arrests for prostitution - was resoundingly rejected. Police and political leaders said it would hamper the fight against sex trafficking.
Nebraska voters approved a ban on race- and gender-based affirmative action, similar to measures previously approved in California, Michigan and Washington.