Two US states rejected proposals to limit abortion rights while others said no to gay marriage, in a mixed message over contentious social issues as Americans elected their first black president.

Results of votes on more than 150 proposed state measures across the country showed a more complex cultural map than last night's historic election of Democrat Barack Obama might indicate.

Download the new Independent Premium app Sharing the full story, not just the headlines

In California, same-sex couples were poised to lose the right to marry, while Florida and Arizona voted to ban gay marriage outright, joining dozens of other states that define marriage as only between a man and a woman.

Attempts to restrict abortion in South Dakota and Colorado met strong voter resistance.

Halting abortion and same-sex marriage are key issues for many conservative Christian voters, an important base for the Republican Party.

With 89 per cent of precincts reporting, the California proposition - which came about half a year after the state court opened the way to gay marriage - was trailing by nearly 4 per centage points.

"We have Obama," Noelle Skool, 29, said of her hopes for change as she checked identification at a popular lesbian bar in San Francisco's Mission district. "It's small steps. Eventually they'll warm up to the fact that, hey, we're all equal."

Mathew Staver, founder of the conservative Liberty Counsel, had success as a proponent of the Florida gay marriage ban but saw the state vote for Obama the Democrat.

"The passage of this amendment is a bright star on an otherwise dismal night, in which America elected the most liberal President in her history," Staver said in a statement.

Colorado voters rejected a measure that would have made abortion the legal equivalent of murder by defining human life as beginning at conception.

Daily coronavirus briefing No hype, just the advice and analysis you need Enter your email address Continue Continue Please enter an email address Email address is invalid Fill out this field Email address is invalid Email already exists. Log in to update your newsletter preferences Register with your social account or click here to log in I would like to receive morning headlines Monday - Friday plus breaking news alerts by email Update newsletter preferences

South Dakota defeated a ban on abortion that, if passed, had been expected to spark a court battle leading to the Supreme Court.

"We defeated it here, and it won't spread to other states," said Sarah Stoesz, president of the local Planned Parenthood chapter. "And now we've started a counter movement in a very conservative part of the country."

In other state ballots, Michigan voted to allow medical use of marijuana, Nebraska ending affirmative action to help minorities and Washington allowing doctor-assisted suicide.