EXCERPT FROM THIS ARTICLE: The issue brought out people to rally on both sides. The Rev. Patrick Wooden of the Upper Room Church of God in Christ in Raleigh calls homosexuality a “deathstyle” and has long fought against those who equate the battle for gay rights with other civil rights struggles.

Mr. Wooden called Tuesday “a great day for the citizens of this great state.”

“They will overwhelmingly support this measure,” he said. “I do believe the majority of most Americans today still believe a marriage is a union between a man and a woman.”

ATLANTA — North Carolina on Tuesday took a big step toward losing its status as the last state in the Southeast without a constitutional amendment making it clear that marriage is legal only when there is a bride and bridegroom.

The Senate, in a 30-16 vote, agreed to let voters decide during the May primaries whether the state Constitution should ban same-sex marriage. The House approved the measure the day before, 75 to 42.

It is already illegal for people of the same sex to marry in North Carolina. If the amendment passes, it will serve to reinforce that ban and make it more difficult for future legislatures to extend marriage rights to gay and lesbian couples.

It could also call into question domestic partnership benefits offered by public institutions and the application of domestic violence laws, said Holning Lau, an associate professor of law at the University of North Carolina. The proposal also would bar the state from sanctioning civil unions. Originally, backers wanted the issue on the ballot in November 2012, where it might help attract voters more likely to vote against President Obama and Gov. Bev Perdue, a Democrat. To quell accusations that the ballot initiative was driven solely by politics, the date was moved to the state’s primary election in May.

Instead, the timing may help ensure passage of the measure, as it will probably receive significant support from those drawn to the polls by the main event: the Republican presidential primary.

As it has in the 29 other states where same-sex marriage is constitutionally illegal, the issue of marriage rights for gay and lesbian couples has been divisive in North Carolina. For nearly a decade, the Democratic-controlled Legislature held off efforts by social conservatives to change the Constitution to ban same-sex marriage.

But with Republicans now in control of both houses, the movement to put the matter to voters found enough support to squeeze through the Legislature.

The issue brought out people to rally on both sides. The Rev. Patrick Wooden of the Upper Room Church of God in Christ in Raleigh calls homosexuality a “deathstyle” and has long fought against those who equate the battle for gay rights with other civil rights struggles.

Mr. Wooden called Tuesday “a great day for the citizens of this great state.”

“They will overwhelmingly support this measure,” he said. “I do believe the majority of most Americans today still believe a marriage is a union between a man and a woman.”

But for people like Vicki Threlfall, 47, who married her partner, Molly O’Neill, also 47, in Massachusetts in 2004, it was a day to sit down with their 10-year-old daughter to try to explain it all.

“We told her that this is something about civil rights,” Ms. Threlfall said. “We said, ‘Do you remember a long time ago how African-Americans weren’t treated fairly? This is like that. There are a lot of people who are afraid and don’t know gay people.’ ”

The ballot measure didn’t come as a surprise to many in the state. But it made Ms. Threlfall and others in cities like Chapel Hill and Raleigh, with large and prominent gay and lesbian communities, brace for months of what will surely be a heated debate over their lives. National organizations on both sides of the issue will be offering monetary and strategic support as the campaign heats up.

“Our intent is to defeat the amendment at polls,” said Alex Miller, the executive director of Equality NC, a statewide advocacy group that will be working with national organizations like the Human Rights Campaign.

“It has been a point of pride that North Carolina was the only Southern state that has never done this. But this is an ongoing war. They have succeeded in throwing up a temporary bulwark against the inevitable tide of history