Of the 153 measures at stake nationwide, the most momentous was the proposed constitutional amendment in California that would limit marriage to heterosexual couples.

Similar measures had prevailed in 27 states before Tuesday's elections, but none were in California's situation - with thousands of gay couples already married following a state Supreme Court ruling in May.

The opposing sides together raised about $70 million, much of it from out of state, to wage their campaigns. The outcome, either way, will have a huge impact on prospects for spreading same-sex marriage to the 47 states that do not allow it.

Though Democrat Barack Obama won the presidential race in California on his way to wrapping up the White House, the vote on same-sex marriage leaned toward instituting the ban...based on more than 80-percent of the ballots counted. A crucial question was how churchgoing black and Hispanic voters - presumably a pro-Obama constituency - would vote on the ballot measure.

According to exit polls, blacks were far more likely than whites or Hispanics to support the ban. Age also was 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.

Obama opposed the California amendment and endorses the concept of broader rights for same-sex couples.

With 90-perrcent of the polls reporting, the YES forces lead the NO camp by a 52 to 48 percent margin.

Amendments to ban gay marriage were approved in Arizona and Florida.  And homosexual forces also suffered defeat in Arkansas, where voters approved a measure banning unmarried couples from serving as adoptive or foster parents. Supporters made clear that gays and lesbians were their main target.

It was not a good night for the pro-life movement in Colorado, South Dakota, and Washington state.

A first-of-its-kind 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.

A 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. Pro-life activists thought the modifications would win approval, but the margin of defeat was similar, about 55 percent to 45 percent of the vote.

In Washington, voters gave solid approval to an initiative modeled after Oregon's "Death with Dignity" law, which allows a terminally ill person to be prescribed lethal medication they can administer to themselves. Since Oregon's law took effect in 1997, more than 340 people - mostly ailing with cancer - have used it to end their lives.

Amid deep economic uncertainty, proposals to cut state income taxes were defeated decisively in North Dakota and Massachusetts.

In San Francisco, an eye-catching local measure - to bar arrests for prostitution - was soundly rejected. Police and political leaders said it would hamper the fight against sex trafficking.