CHARLOTTE – Key African-American leaders are aggressively mobilizing in North Carolina to persuade the state’s black voters to oppose a constitutional amendment to ban gay marriage that is on the ballot on Tuesday here.

Opponents of the provision say the amendment goes further than preventing same-sex marriage, which is already barred by state law, and would effectively prevent civil unions as well. The text of the amendment is “Marriage between one man and one woman is the only domestic legal union that shall be valid or recognized in this State.”

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A recent survey by Public Policy Polling showed that about 55 percent of the state’s voters supported the amendment, while 41 percent opposed it. Most of the state’s Democrats oppose the provision, but a majority of African-Americans are currently backing it, with many arguing their Christian faith convinces them marriage can only be between man and a woman.

Black voters could be as much a fifth of the electorate on Tuesday, when primaries for a number of state races here will also take place. And a sharp shift in the black vote on the issue could help defeat the amendment, which President Obama also opposes.

The North Carolina NAACP and the entire black political establishment have come out against the provision, including former Charlotte mayor Harvey Gantt, the current mayors of Charlotte, Asheville, Durham, and both Democratic candidates for lieutenant governor.

Young black activists have been out in force, making the case that Amendment One, the formal name of the provision, is unnecessary and unfair. And opponents of the amendment are highlighting the role of the National Organization for Marriage, an anti-gay marriage group that, in private memos that were unearthed earlier this year, discussed ways to sow discord between blacks and gays.

But the most interesting opponents of the amendment are black pastors, many of whom are trying to persuade their congregants to change their mind on a very divisive issue.

Bishop Tonyia Rawls of Unity Fellowship Church says the amendment is part of a conservative strategy to divide longtime political allies by “screaming gay and trying to rile up the black community.”

“As black folks, we ought to be the last ones to want to discriminate against anybody as much as we’ve been discriminated against,” says Rev. Reggie Longcrier of Exodus Missionary Outreach Church in Hickory. “We already know that separate is not equal.”

North Carolina is only state in the South that does not already have a constitutional amendment banning gay marriage. The politics of the issue seem to be shifting; six states and the District of Columbia currently allow gay marriage, and several other states are on the verge of legalizing it was as well.

President Obama himself, who has long opposed anti-gay marriage amendments but said in 2008 marriage was between a man and woman, has said his view on gay marriage is “evolving.” His reelection campaign has highlighted his opposition to anti-gay marriage provisions in North Carolina and Minnesota that are on the ballot this year.

And Vice-President Biden noted his support of same-sex marriage in an interview on Sunday.

“While the president does not weigh in on every single ballot measure in every state, the record is clear that the president has long opposed divisive and discriminatory efforts to deny rights and benefits to same sex couples,” an Obama campaign spokesman told the Charlotte Observer. “That’s what the North Carolina ballot initiative would do — it would single out and discriminate against committed gay and lesbian couples — and that’s why the President does not support it.”

But Obama has not spoken publicly on the issue, even in a visit to the state on April 24. Few people here know his position on the issue, and some say they are willing to part ways with him on gay marriage.

“We have great admiration for the president and stand with him on many things, but we don’t have to agree with him on everything,” said Dwayne Walker, pastor of Little Rock AME Zion Church in Charlotte. Walter, a Democrat, recently gave the prayer for an event in Charlotte that was part of the kickoff for the Democratic National Convention, which will take place here in August.

Bishop Phillip Davis, of Nations Ford Community Church in Charlotte says one of the most pressing issues is how we define family. For him, Amendment One is key to helping people understand “that marriage, in and of itself, is a God-ordained and sacred institution.”

In the last few weeks, with a strong media campaign, opponents of the amendment are gaining ground, both overall and with black voters. A PPP poll released on May 1 found that 55 percent plan to vote “Yes” on Tuesday, compared to 58 percent last month. A month ago, 61 percent of blacks said they would support Amendment One, a number that is now down to 53 percent.

But it may not be enough, as most political experts here expect the amendment to pass.