BISMARCK, N.D. (AP) – An 11-state sweep in favor of proposals to ban same-sex marriages shows how much the traditional union of a man and a woman is valued, supporters of the proposals say. Opponents are gearing up for a long battle.

“These laws are not going to last,” Equality North Dakota chair Robert Uebel said after North Dakota voters in the state overwhelmingly approved a constitutional ban on same-sex marriage.

North Dakotans joined voters in Arkansas, Georgia, Kentucky, Michigan, Mississippi, Montana, Oklahoma, Ohio, Utah and Oregon in approving similar measures. North Dakota was one of six states with at least 70 percent support for them.

Christina Rondeau, director of the North Dakota Family Alliance, the group that coordinated an initiative campaign that brought the measure to the state ballot, said the votes came as no surprise, given a history of lopsided outcomes in favor of the issue.

The North Dakota measure limits marriage rights to man-woman couples and restricts civil unions, which extend to same-sex couples many of the same rights of heterosexual, married couples. With all 607 state precincts reporting, the measure won 73 percent approval, or 222,899 votes, to 27 percent, or 81,396 against it, unofficial returns showed.

Uebel said his group would consider its options, though he declined to elaborate.

“These votes are not the end of the discussion. They’re just the beginning, really,” he said.

The measure will add two sentences to Article 11 of the North Dakota Constitution: “Marriage consists only of the legal union between a man and a woman. No other domestic union, however denominated, may be recognized as a marriage, or given the same or substantially equivalent legal effect.”

State officials say it will take effect after it is certified by the state Canvassing Board on Nov. 18.