(Reuters) - North Carolina voters on Tuesday approved a state constitutional amendment that bans same-sex marriage and civil unions, dealing a blow to efforts across the United States to expand gay marriage rights.

The amendment, which says marriage between a man and a woman is the only legally recognized domestic union in the state, passed by a wide margin. With 95 of 100 counties' results reported, about 61 percent of votes backed the amendment.

North Carolina law already blocks gay and lesbian couples from marrying, but the state now joins the rest of the Southeast states in adding the prohibition to its constitution.

Many voters simply viewed the amendment as a vote on same-sex marriage despite efforts by the measure's opponents to broaden the discussion, said Tom Jensen of the Raleigh-based Public Policy Polling firm.

"Anytime in North Carolina you have a majority of Republicans and African Americans on the same side of an issue, that's a very potent combination," Jensen said.

Twenty-eight other state have voter-approved constitutional bans on same-sex marriages, according to the National Conference of State Legislatures.

Massachusetts, Iowa, Vermont, New Hampshire, Connecticut, New York and the District of Columbia allow gay and lesbian nuptials.

Maryland, New Jersey and Washington state have passed laws this year approving same-sex marriage, but Governor Chris Christie vetoed New Jersey's law and opponents in Maryland and Washington are threatening ballot initiatives to overturn those laws.

The vote in North Carolina followed statements by senior officials of President Barack Obama's administration this week which were interpreted as supporting gay marriage.

Vice President Joe Biden said on Sunday he was "absolutely comfortable" with allowing same-sex couples to wed, and Education Secretary Arne Duncan said gay marriage should be legal.

Obama has said he favors civil unions but has stopped short of supporting gay marriage.

Supporters of the amendment in North Carolina, a swing state in the November 6 presidential election, said it would preserve the sanctity of marriage between a man and a woman and make laws forbidding gay marriage harder to repeal.

Opponents said a ban would jeopardize health insurance benefits for unmarried gay and heterosexual couples and signal that the state is unfriendly to a diverse workforce.

Prominent Christian evangelist Billy Graham called on voters to support the measure, while former Democratic President Bill Clinton and some business leaders urged North Carolinians to reject it.

"We will not allow marriage to be redefined in this state. The nation is watching North Carolina, and we have given them a high standard to follow," Tami Fitzgerald, chairwoman of the pro-amendment group Vote for Marriage NC, told supporters at a celebration party.

no laws can be prevention from actions which are natural for people. they humiliate the rights, I guess.

They put stuff like this in the media to distract us from the real issues e.g. the coming WW III

Pathetic