North Carolina will make a ban on gay marriage part of its state constitution. Voters tonight approved a measure that defines marriage as a union between a man and a woman, reports AP. The state already has a law against gay marriage, but legislators wanted to make sure it couldn't get struck down by judges, notes the New York Times. North Carolina will be the 31st state to adopt such an amendment and the last one in the South to do so, adds the Raleigh News & Observer. Incomplete results had the measure up by about 60% to 40%. (More gay marriage stories.)